diff --git a/Borepin/Borepin.UWP/Package.appxmanifest b/Borepin/Borepin.UWP/Package.appxmanifest
index 837242f..f509582 100644
--- a/Borepin/Borepin.UWP/Package.appxmanifest
+++ b/Borepin/Borepin.UWP/Package.appxmanifest
@@ -53,5 +53,7 @@
 
   <Capabilities>
     <Capability Name="internetClient" />
+    <Capability Name="privateNetworkClientServer"/>
+    <Capability Name="allJoyn"/>
   </Capabilities>
 </Package>
\ No newline at end of file
diff --git a/Borepin/Borepin/App.xaml.cs b/Borepin/Borepin/App.xaml.cs
index 400aa87..0ef9f00 100644
--- a/Borepin/Borepin/App.xaml.cs
+++ b/Borepin/Borepin/App.xaml.cs
@@ -12,6 +12,7 @@ using Borepin.PageModel.AddServerProcess;
 using System;
 using Borepin.Service.Storage;
 using NLog;
+using Borepin.Service.ErrorMessage;
 
 namespace Borepin
 {
@@ -69,6 +70,7 @@ namespace Borepin
 
             #region Register Service
             containerRegistry.RegisterSingleton<ILoginStorageService, LoginStorageService>();
+            containerRegistry.RegisterSingleton<IErrorMessageService, ErrorMessageService>();
 
             // NEED PLATFORM SPECIFIC SERVICE
             // IPreferenceStorageService
diff --git a/Borepin/Borepin/Base/ConnectionModelBase.cs b/Borepin/Borepin/Base/ConnectionModelBase.cs
index aed8945..de1759a 100644
--- a/Borepin/Borepin/Base/ConnectionModelBase.cs
+++ b/Borepin/Borepin/Base/ConnectionModelBase.cs
@@ -42,11 +42,9 @@ namespace Borepin.Base
                     {
                         await LoadAPIData().ConfigureAwait(false);
                     }
-                    catch
+                    catch(Exception exception)
                     {
-                        IsConnected = false;
-                        await _API.Disconnect().ConfigureAwait(false);
-                        _API.UnbindEventHandler();
+                        Log.Warn("Load API Data failed", exception);
                     }
                     break;
                 case ConnectionStatusChanged.ConnectionLoss:
@@ -101,10 +99,7 @@ namespace Borepin.Base
                 }
                 catch(Exception exception)
                 {
-                    IsConnected = false;
-                    await _API.Disconnect().ConfigureAwait(false);
-                    _API.UnbindEventHandler();
-                    Log.Error("LoadAPIData failed", exception);
+                    Log.Warn("Load API Data failed", exception);
                 }
             }
         }
diff --git a/Borepin/Borepin/Base/ErrorMessages.cs b/Borepin/Borepin/Base/ErrorMessages.cs
new file mode 100644
index 0000000..c53a915
--- /dev/null
+++ b/Borepin/Borepin/Base/ErrorMessages.cs
@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Borepin.Base
+{
+    public static class ErrorMessages
+    {
+
+    }
+}
diff --git a/Borepin/Borepin/Converter/AllTrueBoolConverter.cs b/Borepin/Borepin/Converter/AllTrueBoolConverter.cs
new file mode 100644
index 0000000..0cfaae5
--- /dev/null
+++ b/Borepin/Borepin/Converter/AllTrueBoolConverter.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Globalization;
+using Xamarin.Forms;
+
+namespace Borepin.Converter
+{
+    public class AllTrueBoolConverter : IMultiValueConverter
+    {
+        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (values == null || !targetType.IsAssignableFrom(typeof(bool)))
+            {
+                return false;
+            }
+
+            foreach (var value in values)
+            {
+                if (!(value is bool b))
+                {
+                    return false;
+                }
+                else if (!b)
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
+        {
+            throw new NotSupportedException();
+        }
+    }
+}
diff --git a/Borepin/Borepin/Page/AddUserPage.xaml b/Borepin/Borepin/Page/AddUserPage.xaml
index 9cdceb5..3ec8089 100644
--- a/Borepin/Borepin/Page/AddUserPage.xaml
+++ b/Borepin/Borepin/Page/AddUserPage.xaml
@@ -3,29 +3,30 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="Borepin.Page.AddUserPage"
              xmlns:converters="clr-namespace:Borepin.Converter"
-             xmlns:resource_text="clr-namespace:Borepin.Resources.Text"
+             xmlns:resource_text="clr-namespace:Borepin.Resources.Text" 
+             xmlns:views="clr-namespace:Borepin.View"
              Title="{x:Static resource_text:TextResource.TITLE_AddUser}">
     <ContentPage.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
             <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
     <ContentPage.Content>
         <StackLayout Padding="20">
-            <StackLayout IsVisible="{Binding IsBusy}">
-                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
-            </StackLayout>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <Label Text="{x:Static resource_text:TextResource.USERNAME}" Style="{StaticResource Style_Label_Property_Title}"></Label>
+            <views:ConnectionStateView/>
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected" />
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Label Text="{x:Static resource_text:TextResource.USERNAME}" Style="{StaticResource Style_Label_Property_Title}"></Label>
                     <Entry Text="{Binding Username}" Keyboard="Url" IsSpellCheckEnabled="false"/>
                     <Label Text="{x:Static resource_text:TextResource.PASSWORD}" Style="{StaticResource Style_Label_Property_Title}"></Label>
                     <Entry Text="{Binding Password}" Keyboard="Url" IsSpellCheckEnabled="false"/>
-                    <Button Text="{x:Static resource_text:TextResource.AddUserPage_AddUser}" Command="{Binding AddUserCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                </StackLayout>
-                <StackLayout IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}">
-                    <Label Text="{x:Static resource_text:TextResource.PLEASECONNECTTOSERVER}"/>
-                </StackLayout>
+                <Button Text="{x:Static resource_text:TextResource.AddUserPage_AddUser}" Command="{Binding AddUserCommand}" Style="{StaticResource Style_Button_Primary}"/>
             </StackLayout>
         </StackLayout>
     </ContentPage.Content>
diff --git a/Borepin/Borepin/Page/MachineListPage.xaml b/Borepin/Borepin/Page/MachineListPage.xaml
index 08fcd0a..2201d09 100644
--- a/Borepin/Borepin/Page/MachineListPage.xaml
+++ b/Borepin/Borepin/Page/MachineListPage.xaml
@@ -1,16 +1,19 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
-             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
-             xmlns:views="clr-namespace:Borepin.View"
-             x:Class="Borepin.Page.MachineListPage"
-             xmlns:converters="clr-namespace:Borepin.Converter"
-             xmlns:resource_text="clr-namespace:Borepin.Resources.Text"
-             Title="{x:Static resource_text:TextResource.TITLE_Machines}">
+<ContentPage
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
+    xmlns:views="clr-namespace:Borepin.View"
+    x:Class="Borepin.Page.MachineListPage"
+    xmlns:converters="clr-namespace:Borepin.Converter"
+    xmlns:resource_text="clr-namespace:Borepin.Resources.Text"
+    Title="{x:Static resource_text:TextResource.TITLE_Machines}"
+    >
     <NavigationPage.TitleView>
         <Button Text="Refresh" HorizontalOptions="End" BackgroundColor="{StaticResource SecondColor}" TextColor="{StaticResource FirstColor}" Command="{Binding RefreshCommand}"/>
     </NavigationPage.TitleView>
     <ContentPage.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
             <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
             <converters:ListNotEmptyConverter x:Key="ListNotEmptyConverter"/>
         </ResourceDictionary>
@@ -18,34 +21,38 @@
     <ContentPage.Content>
         <StackLayout Padding="20">
             <views:ConnectionStateView/>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <Button Text="{x:Static resource_text:TextResource.SCANQR}" Command="{Binding ScanCodeCommand}" Style="{StaticResource Style_Button_Primary}">
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected"/>
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Button Text="{x:Static resource_text:TextResource.SCANQR}" Command="{Binding ScanCodeCommand}" Style="{StaticResource Style_Button_Primary}">
                         <Button.IsVisible>
                             <OnPlatform x:TypeArguments="x:Boolean"
                             iOS="True"
                             Android="True"/>
                         </Button.IsVisible>
                     </Button>
-                    <ListView ItemsSource="{Binding MachineListItemViewModel_List}" SelectionMode="None" SeparatorColor="Transparent" IsGroupingEnabled="True" GroupDisplayBinding="{Binding Category}">
-                        <ListView.GroupHeaderTemplate>
-                            <DataTemplate>
-                                <ViewCell>
-                                    <StackLayout Margin="0, 10, 0, 0">
-                                        <Label Text="{Binding Category}"/>
-                                    </StackLayout>
-                                </ViewCell>
-                            </DataTemplate>
-                        </ListView.GroupHeaderTemplate>
-                        <ListView.ItemTemplate>
-                            <DataTemplate>
-                                <ViewCell>
-                                    <views:MachineListItemView />
-                                </ViewCell>
-                            </DataTemplate>
-                        </ListView.ItemTemplate>
-                    </ListView>
-                </StackLayout>
+                <ListView ItemsSource="{Binding MachineListItemViewModel_List}" SelectionMode="None" SeparatorColor="Transparent" IsGroupingEnabled="True" GroupDisplayBinding="{Binding Category}">
+                    <ListView.GroupHeaderTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <StackLayout Margin="0, 10, 0, 0">
+                                    <Label Text="{Binding Category}"/>
+                                </StackLayout>
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.GroupHeaderTemplate>
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:MachineListItemView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
             </StackLayout>
         </StackLayout>
     </ContentPage.Content>
diff --git a/Borepin/Borepin/Page/MachinePage.xaml b/Borepin/Borepin/Page/MachinePage.xaml
index 3a0576f..99ebf23 100644
--- a/Borepin/Borepin/Page/MachinePage.xaml
+++ b/Borepin/Borepin/Page/MachinePage.xaml
@@ -3,51 +3,61 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="Borepin.Page.MachinePage"
              xmlns:converters="clr-namespace:Borepin.Converter"
-             xmlns:resource_text="clr-namespace:Borepin.Resources.Text"
+             xmlns:resource_text="clr-namespace:Borepin.Resources.Text" 
+             xmlns:views="clr-namespace:Borepin.View"
              Title="{x:Static resource_text:TextResource.TITLE_Machine}">
-    <NavigationPage.TitleView>
-        <Label Text="{Binding MachineItem.State, Converter={StaticResource MachineStateStringConverter}}" FontAttributes="Bold" HorizontalOptions="End" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" WidthRequest="150" Margin="7.5" VerticalOptions="FillAndExpand" FontSize="Small" BackgroundColor="{Binding MachineItem.State, Converter={StaticResource MachineStateColorConverter}}"/>
-    </NavigationPage.TitleView>
     <ContentPage.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
             <converters:MachineStateColorConverter x:Key="MachineStateColorConverter"/>
             <converters:MachineStateStringConverter x:Key="MachineStateStringConverter"/>
             <converters:IsNotNullBoolConverter x:Key="IsNotNullBoolConverter"/>
-            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
+    <NavigationPage.TitleView>
+        <Label Text="{Binding MachineItem.State, Converter={StaticResource MachineStateStringConverter}}" FontAttributes="Bold" HorizontalOptions="End" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" WidthRequest="150" Margin="7.5" VerticalOptions="FillAndExpand" FontSize="Small" BackgroundColor="{Binding MachineItem.State, Converter={StaticResource MachineStateColorConverter}}">
+            <Label.IsVisible>
+                <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                    <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                    <Binding Path="IsConnected" />
+                </MultiBinding>
+            </Label.IsVisible>
+        </Label>
+    </NavigationPage.TitleView>
     <ContentPage.Content>
         <ScrollView>
             <StackLayout Padding="20">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <StackLayout IsVisible="{Binding IsBusy}">
-                        <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+                <views:ConnectionStateView/>
+                <StackLayout>
+                    <StackLayout.IsVisible>
+                        <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                            <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                            <Binding Path="IsConnected" />
+                        </MultiBinding>
+                    </StackLayout.IsVisible>
+                    <Label Text="{Binding MachineItem.Name}" Style="{StaticResource LabelStyle_Title}"/>
+                    <Label Text="{Binding MachineItem.Description}" Style="{StaticResource Style_Label_Text_Center}"/>
+                    <StackLayout Orientation="Horizontal" IsVisible="{Binding MachineItem.CurrentUser, Converter={StaticResource IsNotNullBoolConverter}}">
+                        <Label Text="{x:Static resource_text:TextResource.MachinePage_CurrentUser}" Style="{StaticResource Style_Label_Property_Title}"/>
+                        <Label Text="{Binding MachineItem.CurrentUser.Username}" Style="{StaticResource Style_Label_Property_Text}"/>
                     </StackLayout>
-                    <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                        <Label Text="{Binding MachineItem.Name}" Style="{StaticResource LabelStyle_Title}"/>
-                        <Label Text="{Binding MachineItem.Description}" Style="{StaticResource Style_Label_Text_Center}"/>
-                        <StackLayout Orientation="Horizontal" IsVisible="{Binding MachineItem.CurrentUser, Converter={StaticResource IsNotNullBoolConverter}}">
-                            <Label Text="{x:Static resource_text:TextResource.MachinePage_CurrentUser}" Style="{StaticResource Style_Label_Property_Title}"/>
-                            <Label Text="{Binding MachineItem.CurrentUser.Username}" Style="{StaticResource Style_Label_Property_Text}"/>
-                        </StackLayout>
 
-                        <Button Text="{x:Static resource_text:TextResource.MachinePage_Use}" IsVisible="{Binding MachineItem.CanUse}" Command="{Binding UseMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                        <Label Text="{x:Static resource_text:TextResource.MachinePage_CanNotUseByPermission}" IsVisible="{Binding MachineItem.CanNotUseByPermission}" Style="{StaticResource Style_Label_Text_Center}"/>
-                        <Button Text="{x:Static resource_text:TextResource.MachinePage_GiveBack}" IsVisible="{Binding MachineItem.CanInUse}" Command="{Binding GiveBackMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                        <Button VerticalOptions="End" Text="{x:Static resource_text:TextResource.MachinePage_OpenWiki}" IsVisible="{Binding MachineItem.Wiki, Converter={StaticResource IsNotNullBoolConverter}}" Command="{Binding OpenWikiCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                        <StackLayout Grid.Row="2" VerticalOptions="End" IsVisible="{Binding MachineItem.CanManage}">
-                            <Label Text="{x:Static resource_text:TextResource.MachinePage_ManageMachine}" Style="{StaticResource Style_Label_Property_Title}"/>
-                            <StackLayout Margin="10, 0, 0, 20" Orientation="Horizontal" IsVisible="{Binding MachineItem.LastUser, Converter={StaticResource IsNotNullBoolConverter}}">
-                                <Label Text="{x:Static resource_text:TextResource.MachinePage_LastUser}" Style="{StaticResource Style_Label_Property_Title}"/>
-                                <Label Text="{Binding MachineItem.LastUser.Username}" Style="{StaticResource Style_Label_Property_Text}" Margin="10, 0, 0, 0"/>
-                            </StackLayout>
-                            <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceFree}" Command="{Binding ForceFreeMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                            <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceBlock}" Command="{Binding ForceBlockMachineCommand}" Style="{StaticResource Style_Button_Admin}"/>
-                            <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceDisable}" Command="{Binding ForceDisableMachineCommand}" Style="{StaticResource Style_Button_Admin}"/>
+                    <Button Text="{x:Static resource_text:TextResource.MachinePage_Use}" IsVisible="{Binding MachineItem.CanUse}" Command="{Binding UseMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
+                    <Label Text="{x:Static resource_text:TextResource.MachinePage_CanNotUseByPermission}" IsVisible="{Binding MachineItem.CanNotUseByPermission}" Style="{StaticResource Style_Label_Text_Center}"/>
+                    <Button Text="{x:Static resource_text:TextResource.MachinePage_GiveBack}" IsVisible="{Binding MachineItem.CanInUse}" Command="{Binding GiveBackMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
+                    <Button VerticalOptions="End" Text="{x:Static resource_text:TextResource.MachinePage_OpenWiki}" IsVisible="{Binding MachineItem.Wiki, Converter={StaticResource IsNotNullBoolConverter}}" Command="{Binding OpenWikiCommand}" Style="{StaticResource Style_Button_Primary}"/>
+                    <StackLayout Grid.Row="2" VerticalOptions="End" IsVisible="{Binding MachineItem.CanManage}">
+                        <Label Text="{x:Static resource_text:TextResource.MachinePage_ManageMachine}" Style="{StaticResource Style_Label_Property_Title}"/>
+                        <StackLayout Margin="10, 0, 0, 20" Orientation="Horizontal" IsVisible="{Binding MachineItem.LastUser, Converter={StaticResource IsNotNullBoolConverter}}">
+                            <Label Text="{x:Static resource_text:TextResource.MachinePage_LastUser}" Style="{StaticResource Style_Label_Property_Title}"/>
+                            <Label Text="{Binding MachineItem.LastUser.Username}" Style="{StaticResource Style_Label_Property_Text}" Margin="10, 0, 0, 0"/>
                         </StackLayout>
+                        <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceFree}" Command="{Binding ForceFreeMachineCommand}" Style="{StaticResource Style_Button_Primary}"/>
+                        <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceBlock}" Command="{Binding ForceBlockMachineCommand}" Style="{StaticResource Style_Button_Admin}"/>
+                        <Button Text="{x:Static resource_text:TextResource.MachinePage_ForceDisable}" Command="{Binding ForceDisableMachineCommand}" Style="{StaticResource Style_Button_Admin}"/>
                     </StackLayout>
                 </StackLayout>
-                <Label Text="{x:Static resource_text:TextResource.PLEASECONNECTTOSERVER}" IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}"></Label>
             </StackLayout>
         </ScrollView>
     </ContentPage.Content>
diff --git a/Borepin/Borepin/Page/ProfilePage.xaml b/Borepin/Borepin/Page/ProfilePage.xaml
index 2a1d6fb..6f21c73 100644
--- a/Borepin/Borepin/Page/ProfilePage.xaml
+++ b/Borepin/Borepin/Page/ProfilePage.xaml
@@ -3,7 +3,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="Borepin.Page.ProfilePage"
              xmlns:converters="clr-namespace:Borepin.Converter"
-             xmlns:resource_text="clr-namespace:Borepin.Resources.Text"
+             xmlns:resource_text="clr-namespace:Borepin.Resources.Text" xmlns:views="clr-namespace:Borepin.View"
              Title="{x:Static resource_text:TextResource.TITLE_Profile}">
     <ContentPage.Resources>
         <ResourceDictionary>
@@ -12,21 +12,20 @@
     </ContentPage.Resources>
     <ContentPage.Content>
         <StackLayout Padding="20">
-            <StackLayout IsVisible="{Binding IsBusy}">
-                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
-            </StackLayout>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <Label Text="{Binding Username}" Style="{StaticResource LabelStyle_Title}"/>
-                    <StackLayout IsVisible="{Binding CanManage}">
-                        <Label Text="{x:Static resource_text:TextResource.ProfilePage_ChangePassword}" Style="{StaticResource Style_Label_Property_Title}"/>
-                        <Entry Placeholder="{x:Static resource_text:TextResource.ProfilePage_OldPassword}" Text="{Binding OldPassword}"/>
-                        <Entry Placeholder="{x:Static resource_text:TextResource.ProfilePage_NewPassword}" Text="{Binding NewPassword}"/>
-                        <Button Text="{x:Static resource_text:TextResource.ProfilePage_UpdatePassword}" Command="{Binding UpdatePasswordCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                    </StackLayout>
-                </StackLayout>
-                <StackLayout IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}">
-                    <Label Text="{x:Static resource_text:TextResource.PLEASECONNECTTOSERVER}"/>
+            <views:ConnectionStateView/>
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected" />
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Label Text="{Binding Username}" Style="{StaticResource LabelStyle_Title}"/>
+                <StackLayout IsVisible="{Binding CanManage}">
+                    <Label Text="{x:Static resource_text:TextResource.ProfilePage_ChangePassword}" Style="{StaticResource Style_Label_Property_Title}"/>
+                    <Entry Placeholder="{x:Static resource_text:TextResource.ProfilePage_OldPassword}" Text="{Binding OldPassword}"/>
+                    <Entry Placeholder="{x:Static resource_text:TextResource.ProfilePage_NewPassword}" Text="{Binding NewPassword}"/>
+                    <Button Text="{x:Static resource_text:TextResource.ProfilePage_UpdatePassword}" Command="{Binding UpdatePasswordCommand}" Style="{StaticResource Style_Button_Primary}"/>
                 </StackLayout>
             </StackLayout>
         </StackLayout>
diff --git a/Borepin/Borepin/Page/UserListPage.xaml b/Borepin/Borepin/Page/UserListPage.xaml
index 47f1c44..4b990d5 100644
--- a/Borepin/Borepin/Page/UserListPage.xaml
+++ b/Borepin/Borepin/Page/UserListPage.xaml
@@ -11,36 +11,36 @@
     </NavigationPage.TitleView>
     <ContentPage.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
             <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
             <converters:ListNotEmptyConverter x:Key="ListNotEmptyConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
     <ContentPage.Content>
         <StackLayout Padding="20">
-            <StackLayout IsVisible="{Binding IsBusy}">
-                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
-            </StackLayout>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <Button Text="{x:Static resource_text:TextResource.UserListPage_AddUser}" Command="{Binding AddUserCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                    <SearchBar Text="{Binding SearchUsername}" SearchCommand="{Binding SearchUserCommand}">
-                        <SearchBar.Behaviors>
-                            <prism:EventToCommandBehavior EventName="TextChanged" Command="{Binding SearchUserCommand}"/>
-                        </SearchBar.Behaviors>
-                    </SearchBar>
-                    <ListView ItemsSource="{Binding FilteredUserListItemViewModel_List}" SelectionMode="None" SeparatorColor="Transparent">
-                        <ListView.ItemTemplate>
-                            <DataTemplate>
-                                <ViewCell>
-                                    <views:UserListItemView />
-                                </ViewCell>
-                            </DataTemplate>
-                        </ListView.ItemTemplate>
-                    </ListView>
-                </StackLayout>
-                <StackLayout IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}">
-                    <Label Text="{x:Static resource_text:TextResource.PLEASECONNECTTOSERVER}"/>
-                </StackLayout>
+            <views:ConnectionStateView/>
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected" />
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Button Text="{x:Static resource_text:TextResource.UserListPage_AddUser}" Command="{Binding AddUserCommand}" Style="{StaticResource Style_Button_Primary}"/>
+                <SearchBar Text="{Binding SearchUsername}" SearchCommand="{Binding SearchUserCommand}">
+                    <SearchBar.Behaviors>
+                        <prism:EventToCommandBehavior EventName="TextChanged" Command="{Binding SearchUserCommand}"/>
+                    </SearchBar.Behaviors>
+                </SearchBar>
+                <ListView ItemsSource="{Binding FilteredUserListItemViewModel_List}" SelectionMode="None" SeparatorColor="Transparent">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:UserListItemView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
             </StackLayout>
         </StackLayout>
     </ContentPage.Content>
diff --git a/Borepin/Borepin/Page/UserPage.xaml b/Borepin/Borepin/Page/UserPage.xaml
index 4ae7dc4..da07ab6 100644
--- a/Borepin/Borepin/Page/UserPage.xaml
+++ b/Borepin/Borepin/Page/UserPage.xaml
@@ -8,39 +8,39 @@
              Title="{x:Static resource_text:TextResource.TITLE_User}">
     <ContentPage.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
             <converters:MachineStateColorConverter x:Key="MachineStateColorConverter"/>
             <converters:MachineStateStringConverter x:Key="MachineStateStringConverter"/>
             <converters:IsNotNullBoolConverter x:Key="IsNotNullBoolConverter"/>
-            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
     <ContentPage.Content>
         <StackLayout Padding="20">
-            <StackLayout IsVisible="{Binding IsBusy}">
-                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
-            </StackLayout>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected}">
-                    <Label Text="{Binding UserItem.Username}" Style="{StaticResource LabelStyle_Title}"/>
-                    <ListView ItemsSource="{Binding PermissionSelectViewModel_List}" SelectionMode="None" SeparatorColor="Transparent">
-                        <ListView.ItemTemplate>
-                            <DataTemplate>
-                                <ViewCell>
-                                    <views:PermissionSelectView />
-                                </ViewCell>
-                            </DataTemplate>
-                        </ListView.ItemTemplate>
-                    </ListView>
-                    <StackLayout IsVisible="{Binding CanAdmin}">
-                        <Label Text="{x:Static resource_text:TextResource.UserPage_ChangePassword}" Style="{StaticResource Style_Label_Property_Title}"/>
-                        <Entry Placeholder="{x:Static resource_text:TextResource.UserPage_NewPassword}" Text="{Binding NewPassword}"/>
-                        <Button Text="{x:Static resource_text:TextResource.UserPage_UpdatePassword}" Command="{Binding UpdatePasswordCommand}" Style="{StaticResource Style_Button_Primary}"/>
-                    </StackLayout>
-                    <Button Grid.Row="1" Text="{x:Static resource_text:TextResource.DELETE}" Command="{Binding DeleteCommand}" Style="{StaticResource Style_Button_Admin}" VerticalOptions="End"/>
-                    </StackLayout>
-                <StackLayout IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}">
-                    <Label Text="{x:Static resource_text:TextResource.PLEASECONNECTTOSERVER}"/>
+            <views:ConnectionStateView/>
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected" />
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Label Text="{Binding UserItem.Username}" Style="{StaticResource LabelStyle_Title}"/>
+                <ListView ItemsSource="{Binding PermissionSelectViewModel_List}" SelectionMode="None" SeparatorColor="Transparent">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:PermissionSelectView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+                <StackLayout IsVisible="{Binding CanAdmin}">
+                    <Label Text="{x:Static resource_text:TextResource.UserPage_ChangePassword}" Style="{StaticResource Style_Label_Property_Title}"/>
+                    <Entry Placeholder="{x:Static resource_text:TextResource.UserPage_NewPassword}" Text="{Binding NewPassword}"/>
+                    <Button Text="{x:Static resource_text:TextResource.UserPage_UpdatePassword}" Command="{Binding UpdatePasswordCommand}" Style="{StaticResource Style_Button_Primary}"/>
                 </StackLayout>
+                <Button Grid.Row="1" Text="{x:Static resource_text:TextResource.DELETE}" Command="{Binding DeleteCommand}" Style="{StaticResource Style_Button_Admin}" VerticalOptions="End"/>
             </StackLayout>
         </StackLayout>
     </ContentPage.Content>
diff --git a/Borepin/Borepin/PageModel/AddServerProcess/SelectServerPageModel.cs b/Borepin/Borepin/PageModel/AddServerProcess/SelectServerPageModel.cs
index 62b6e15..859465b 100644
--- a/Borepin/Borepin/PageModel/AddServerProcess/SelectServerPageModel.cs
+++ b/Borepin/Borepin/PageModel/AddServerProcess/SelectServerPageModel.cs
@@ -1,4 +1,5 @@
 using Borepin.Base;
+using Borepin.Service.ErrorMessage;
 using FabAccessAPI;
 using FabAccessAPI.Exceptions;
 using Prism.Commands;
@@ -16,11 +17,14 @@ namespace Borepin.PageModel.AddServerProcess
     {
         #region Private Fields
         private ConnectionData _ConnectionData;
+        private IErrorMessageService _ErrorMessageService;
         #endregion
 
         #region Constructors
-        public SelectServerPageModel(INavigationService navigationService, IPageDialogService pageDialogService) : base(navigationService, pageDialogService)
+        public SelectServerPageModel(INavigationService navigationService, IPageDialogService pageDialogService, IErrorMessageService errorMessageService) : base(navigationService, pageDialogService)
         {
+            _ErrorMessageService = errorMessageService;
+
             ConnectToServerCommand = new DelegateCommand(async () => await ConnectToServerExecute().ConfigureAwait(false));
             DetectLocalServerCommand = new DelegateCommand(DetectHostCommandExecute);
             ScanCodeCommand = new DelegateCommand(ScanCodeCommandExecute);
@@ -120,15 +124,10 @@ namespace Borepin.PageModel.AddServerProcess
                 API api = new API();
                 await api.TryToConnect(_ConnectionData).ConfigureAwait(false);
             }
-            catch(ConnectionException)
+            catch(Exception exception)
             {
-                Device.BeginInvokeOnMainThread(async () =>
-                {
-                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnableServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-
-                    IsBusy = false;
-                });
-
+                _ErrorMessageService.DisplayConnectFailedMessage(exception);
+                IsBusy = false;
                 return;
             }
 
diff --git a/Borepin/Borepin/PageModel/MachineListPageModel.cs b/Borepin/Borepin/PageModel/MachineListPageModel.cs
index d85d9fa..6e05381 100644
--- a/Borepin/Borepin/PageModel/MachineListPageModel.cs
+++ b/Borepin/Borepin/PageModel/MachineListPageModel.cs
@@ -145,7 +145,15 @@ namespace Borepin.PageModel
         {
             if(_API.IsConnected)
             {
-                await LoadAPIData().ConfigureAwait(true);
+                try
+                {
+                    await LoadAPIData().ConfigureAwait(true);
+                }
+                catch
+                {
+                    // TODO
+                }
+                
             }
             
             IsRefreshing = false;
diff --git a/Borepin/Borepin/PageModel/ServerListPageModel.cs b/Borepin/Borepin/PageModel/ServerListPageModel.cs
index 26dff07..7b49db4 100644
--- a/Borepin/Borepin/PageModel/ServerListPageModel.cs
+++ b/Borepin/Borepin/PageModel/ServerListPageModel.cs
@@ -36,7 +36,7 @@ namespace Borepin.PageModel
             List<Task> tasks = new List<Task>();
 
             IList<ConnectionData> list = await _LoginStorageService.GetList().ConfigureAwait(false);
-            if (_API.IsConnected)
+            if (_API.IsConnected || _API.IsConnecting)
             {
                 ActiveConnection = new ServerListItemViewModel(_NavigationService, _PageDialogService);
                 await ActiveConnection.LoadInstance(_API.ConnectionData).ConfigureAwait(false);
diff --git a/Borepin/Borepin/PageModel/ServerPageModel.cs b/Borepin/Borepin/PageModel/ServerPageModel.cs
index 2212e3c..cce4a94 100644
--- a/Borepin/Borepin/PageModel/ServerPageModel.cs
+++ b/Borepin/Borepin/PageModel/ServerPageModel.cs
@@ -1,6 +1,7 @@
 using Borepin.Base;
 using Borepin.Base.Exceptions;
 using Borepin.Service;
+using Borepin.Service.ErrorMessage;
 using Borepin.Service.Storage;
 using FabAccessAPI;
 using FabAccessAPI.Exceptions;
@@ -22,14 +23,16 @@ namespace Borepin.PageModel
         #region Private Fields
         private readonly IDialogService _DialogService;
         private readonly ILoginStorageService _LoginStorageService;
+        private readonly IErrorMessageService _ErrorMessageService;
         private bool IsDialog = false;
         #endregion
 
         #region Constructors
-        public ServerPageModel(INavigationService navigationService, IPageDialogService pageDialogService, IAPIService apiService, IDialogService dialogService, ILoginStorageService loginStorageService) : base(navigationService, pageDialogService, apiService)
+        public ServerPageModel(INavigationService navigationService, IPageDialogService pageDialogService, IAPIService apiService, IDialogService dialogService, ILoginStorageService loginStorageService, IErrorMessageService errorMessageService) : base(navigationService, pageDialogService, apiService)
         {
             _DialogService = dialogService;
             _LoginStorageService = loginStorageService;
+            _ErrorMessageService = errorMessageService;
 
             ConnectCommand = new DelegateCommand(async () => await ConnectCommandExecute().ConfigureAwait(false));
             DisconnectCommand = new DelegateCommand(async () => await DisonnectCommandExecute().ConfigureAwait(false));
@@ -52,7 +55,7 @@ namespace Borepin.PageModel
                     throw new InstanceIncorrectException();
                 }
 
-                if(_API.IsConnected && Connection_Item != null)
+                if((_API.IsConnected || _API.IsConnecting) && Connection_Item != null)
                 {
                     InstanceIsActiveConnection = Connection_Item.Equals(_API.ConnectionData);
                 }
@@ -125,31 +128,16 @@ namespace Borepin.PageModel
             if(_API.IsConnected)
             {
                 await _API.Disconnect().ConfigureAwait(true);
-                _API.UnbindEventHandler();
             }
 
             try
             {
                 await _API.Connect(Connection_Item).ConfigureAwait(false);
             }
-            catch(ConnectionException)
+            catch(Exception exception)
             {
-                Device.BeginInvokeOnMainThread(async () =>
-                {
-                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnableServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-
-                    IsBusy = false;
-                });
-                return;
-            }
-            catch(AuthenticationFailedException)
-            {
-                Device.BeginInvokeOnMainThread(async () =>
-                {
-                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_AuthServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-
-                    IsBusy = false;
-                });
+                _ErrorMessageService.DisplayConnectFailedMessage(exception);
+                IsBusy = false;
                 return;
             }
 
diff --git a/Borepin/Borepin/PageModel/StartPageModel.cs b/Borepin/Borepin/PageModel/StartPageModel.cs
index 59bdec5..34636b7 100644
--- a/Borepin/Borepin/PageModel/StartPageModel.cs
+++ b/Borepin/Borepin/PageModel/StartPageModel.cs
@@ -1,5 +1,6 @@
 using Borepin.Base;
 using Borepin.Service;
+using Borepin.Service.ErrorMessage;
 using Borepin.Service.Storage;
 using FabAccessAPI;
 using FabAccessAPI.Exceptions;
@@ -19,12 +20,14 @@ namespace Borepin.PageModel
     {
         #region Private Fields
         private readonly ILoginStorageService _LoginStorageService;
+        private readonly IErrorMessageService _ErrorMessageService;
         #endregion
 
         #region Constructors
-        public StartPageModel(INavigationService navigationService, IPageDialogService pageDialogService, IAPIService apiService, ILoginStorageService loginStorageService) : base(navigationService, pageDialogService, apiService)
+        public StartPageModel(INavigationService navigationService, IPageDialogService pageDialogService, IAPIService apiService, ILoginStorageService loginStorageService, IErrorMessageService errorMessageService) : base(navigationService, pageDialogService, apiService)
         {
             _LoginStorageService = loginStorageService;
+            _ErrorMessageService = errorMessageService;
         }
         #endregion
 
@@ -70,33 +73,9 @@ namespace Borepin.PageModel
                         }
                     });
                 }
-                catch (ConnectionException)
+                catch (Exception exception)
                 {
-                    Device.BeginInvokeOnMainThread(async () =>
-                    {
-                        await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnableServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-                    });
-                }
-                catch (AuthenticationFailedException)
-                {
-                    Device.BeginInvokeOnMainThread(async () =>
-                    {
-                        await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_AuthServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-                    });
-                }
-                catch (InvalidCredentialsException)
-                {
-                    Device.BeginInvokeOnMainThread(async () =>
-                    {
-                        await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_CredentialsInvalid, Resources.Text.TextResource.OK).ConfigureAwait(false);
-                    });
-                }
-                catch (Exception)
-                {
-                    Device.BeginInvokeOnMainThread(async () =>
-                    {
-                        await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_UnexpectedError, Resources.Text.TextResource.ALERT_UnableServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
-                    });
+                    _ErrorMessageService.DisplayConnectFailedMessage(exception);
                 }
 
                 if (_API.IsConnected == false)
diff --git a/Borepin/Borepin/PageModel/UserListPageModel.cs b/Borepin/Borepin/PageModel/UserListPageModel.cs
index 220d479..937ad9e 100644
--- a/Borepin/Borepin/PageModel/UserListPageModel.cs
+++ b/Borepin/Borepin/PageModel/UserListPageModel.cs
@@ -90,7 +90,14 @@ namespace Borepin.PageModel
         {
             if(_API.IsConnected)
             {
-                await LoadAPIData().ConfigureAwait(true);
+                try
+                {
+                    await LoadAPIData().ConfigureAwait(true);
+                }
+                catch (Exception)
+                {
+                    // TODO
+                }
             }
             
             IsRefreshing = false;
diff --git a/Borepin/Borepin/Resources/Text/TextResource.Designer.cs b/Borepin/Borepin/Resources/Text/TextResource.Designer.cs
index 3b7573e..60a9afa 100644
--- a/Borepin/Borepin/Resources/Text/TextResource.Designer.cs
+++ b/Borepin/Borepin/Resources/Text/TextResource.Designer.cs
@@ -170,6 +170,15 @@ namespace Borepin.Resources.Text {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die Authentication failed ähnelt.
+        /// </summary>
+        internal static string ALERT_AuthFailed {
+            get {
+                return ResourceManager.GetString("ALERT_AuthFailed", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Unable to authenticate to server. ähnelt.
         /// </summary>
@@ -179,6 +188,15 @@ namespace Borepin.Resources.Text {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die SASL Mechanism is not supported- ähnelt.
+        /// </summary>
+        internal static string ALERT_BadMechanism {
+            get {
+                return ResourceManager.GetString("ALERT_BadMechanism", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Connection failed ähnelt.
         /// </summary>
@@ -188,6 +206,15 @@ namespace Borepin.Resources.Text {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die Connection time exceeded. ähnelt.
+        /// </summary>
+        internal static string ALERT_ConnectionTimeout {
+            get {
+                return ResourceManager.GetString("ALERT_ConnectionTimeout", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Credentials are invalid. ähnelt.
         /// </summary>
@@ -224,6 +251,24 @@ namespace Borepin.Resources.Text {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die SASL Authenticaiton failed ähnelt.
+        /// </summary>
+        internal static string ALERT_SASLAuth {
+            get {
+                return ResourceManager.GetString("ALERT_SASLAuth", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die TLS certificate is invalid. ähnelt.
+        /// </summary>
+        internal static string ALERT_TLSInvalid {
+            get {
+                return ResourceManager.GetString("ALERT_TLSInvalid", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Unable to connect to server. ähnelt.
         /// </summary>
@@ -296,6 +341,33 @@ namespace Borepin.Resources.Text {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die Connecting to Server ... ähnelt.
+        /// </summary>
+        internal static string ConnectionStatus_Connecting {
+            get {
+                return ResourceManager.GetString("ConnectionStatus_Connecting", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die No Connection to Server ähnelt.
+        /// </summary>
+        internal static string ConnectionStatus_NoConnection {
+            get {
+                return ResourceManager.GetString("ConnectionStatus_NoConnection", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die Please select a Server. ähnelt.
+        /// </summary>
+        internal static string ConnectionStatus_NotConnected {
+            get {
+                return ResourceManager.GetString("ConnectionStatus_NotConnected", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Delete ähnelt.
         /// </summary>
@@ -558,15 +630,6 @@ namespace Borepin.Resources.Text {
             }
         }
         
-        /// <summary>
-        ///   Sucht eine lokalisierte Zeichenfolge, die Please connect to Server ähnelt.
-        /// </summary>
-        internal static string PLEASECONNECTTOSERVER {
-            get {
-                return ResourceManager.GetString("PLEASECONNECTTOSERVER", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Change Password ähnelt.
         /// </summary>
diff --git a/Borepin/Borepin/Resources/Text/TextResource.resx b/Borepin/Borepin/Resources/Text/TextResource.resx
index faa73d3..1b7a9cf 100644
--- a/Borepin/Borepin/Resources/Text/TextResource.resx
+++ b/Borepin/Borepin/Resources/Text/TextResource.resx
@@ -151,39 +151,71 @@ You can also put down several servers and then connect to the desired server.</v
   </data>
   <data name="ALERT_AddressInvalid" xml:space="preserve">
     <value>Server address is invaild.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_AddUserFailed" xml:space="preserve">
     <value>Add User failed</value>
+    <comment>Message Content</comment>
+  </data>
+  <data name="ALERT_AuthFailed" xml:space="preserve">
+    <value>Authentication failed</value>
+    <comment>Message Title</comment>
   </data>
   <data name="ALERT_AuthServer" xml:space="preserve">
     <value>Unable to authenticate to server.</value>
+    <comment>Message Content</comment>
+  </data>
+  <data name="ALERT_BadMechanism" xml:space="preserve">
+    <value>SASL Mechanism is not supported-</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_ConnectionFailed" xml:space="preserve">
     <value>Connection failed</value>
+    <comment>Message Title</comment>
+  </data>
+  <data name="ALERT_ConnectionTimeout" xml:space="preserve">
+    <value>Connection time exceeded.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_CredentialsInvalid" xml:space="preserve">
     <value>Credentials are invalid.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_DuplicateConnection" xml:space="preserve">
     <value>Connection already exist. Please delete old Connection before adding the new Connection.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_PasswordInvalid" xml:space="preserve">
     <value>Password is invalid.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_QRInvalid" xml:space="preserve">
     <value>QR Code is invalid</value>
+    <comment>Message Content</comment>
+  </data>
+  <data name="ALERT_SASLAuth" xml:space="preserve">
+    <value>SASL Authenticaiton failed</value>
+    <comment>Message Content</comment>
+  </data>
+  <data name="ALERT_TLSInvalid" xml:space="preserve">
+    <value>TLS certificate is invalid.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_UnableServer" xml:space="preserve">
     <value>Unable to connect to server.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_UnexpectedError" xml:space="preserve">
     <value>Unexpected Error.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_UserExist" xml:space="preserve">
     <value>User allready exist.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="ALERT_UsernameInvalid" xml:space="preserve">
     <value>Username is invalid.</value>
+    <comment>Message Content</comment>
   </data>
   <data name="Bionade" xml:space="preserve">
     <value>It's Bionade</value>
@@ -197,6 +229,15 @@ You can also put down several servers and then connect to the desired server.</v
   <data name="CONFIRM" xml:space="preserve">
     <value>Confirm</value>
   </data>
+  <data name="ConnectionStatus_Connecting" xml:space="preserve">
+    <value>Connecting to Server ...</value>
+  </data>
+  <data name="ConnectionStatus_NoConnection" xml:space="preserve">
+    <value>No Connection to Server</value>
+  </data>
+  <data name="ConnectionStatus_NotConnected" xml:space="preserve">
+    <value>Please select a Server.</value>
+  </data>
   <data name="DELETE" xml:space="preserve">
     <value>Delete</value>
   </data>
@@ -285,9 +326,6 @@ Ask in your Space if you can be trained on the machine to be unlocked for the ma
   <data name="PASSWORD" xml:space="preserve">
     <value>Password</value>
   </data>
-  <data name="PLEASECONNECTTOSERVER" xml:space="preserve">
-    <value>Please connect to Server</value>
-  </data>
   <data name="ProfilePage_ChangePassword" xml:space="preserve">
     <value>Change Password</value>
   </data>
diff --git a/Borepin/Borepin/Service/ErrorMessage/ErrorMessageService.cs b/Borepin/Borepin/Service/ErrorMessage/ErrorMessageService.cs
new file mode 100644
index 0000000..40e3ff6
--- /dev/null
+++ b/Borepin/Borepin/Service/ErrorMessage/ErrorMessageService.cs
@@ -0,0 +1,108 @@
+using Capnp.Rpc;
+using FabAccessAPI.Exceptions;
+using FabAccessAPI.Exceptions.SASL;
+using Prism.Services;
+using Xamarin.Forms;
+
+namespace Borepin.Service.ErrorMessage
+{
+    public class ErrorMessageService : IErrorMessageService
+    {
+        #region Private Members
+        private IPageDialogService _PageDialogService;
+        #endregion
+
+        #region Constructor
+        public ErrorMessageService(IPageDialogService pageDialogService)
+        {
+            _PageDialogService = pageDialogService;
+        }
+        #endregion
+
+        #region Methods to Display Connection Error
+
+        public void DisplayConnectFailedMessage(System.Exception exception)
+        {
+            if(exception is ConnectionException)
+            {
+                DisplayConnectionMessage(exception as ConnectionException);
+            }
+            else if(exception is AuthenticationException)
+            {
+                DisplayAuthenticationMessage(exception as AuthenticationException);
+            }
+            else
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnexpectedError, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+        }
+
+        public void DisplayAuthenticationMessage(AuthenticationException exception)
+        {
+            if (exception.InnerException is BadMechanismException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_AuthFailed, Resources.Text.TextResource.ALERT_BadMechanism, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else if (exception.InnerException is InvalidCredentialsException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_AuthFailed, Resources.Text.TextResource.ALERT_CredentialsInvalid, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else if (exception.InnerException is AuthenticationFailedException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_AuthFailed, Resources.Text.TextResource.ALERT_SASLAuth, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_AuthFailed, Resources.Text.TextResource.ALERT_UnexpectedError, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+        }
+
+        public void DisplayConnectionMessage(ConnectionException exception)
+        {
+            if(exception.InnerException is System.Security.Authentication.AuthenticationException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_TLSInvalid, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else if(exception.InnerException is FabAccessAPI.Exceptions.TimeoutException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_ConnectionTimeout, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else if(exception.InnerException is RpcException)
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnableServer, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+            else
+            {
+                Device.BeginInvokeOnMainThread(async () =>
+                {
+                    await _PageDialogService.DisplayAlertAsync(Resources.Text.TextResource.ALERT_ConnectionFailed, Resources.Text.TextResource.ALERT_UnexpectedError, Resources.Text.TextResource.OK).ConfigureAwait(false);
+                });
+            }
+        }
+        #endregion
+    }
+}
diff --git a/Borepin/Borepin/Service/ErrorMessage/IErrorMessageService.cs b/Borepin/Borepin/Service/ErrorMessage/IErrorMessageService.cs
new file mode 100644
index 0000000..01f60a8
--- /dev/null
+++ b/Borepin/Borepin/Service/ErrorMessage/IErrorMessageService.cs
@@ -0,0 +1,14 @@
+using FabAccessAPI.Exceptions;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Borepin.Service.ErrorMessage
+{
+    public interface IErrorMessageService
+    {
+        void DisplayConnectFailedMessage(Exception exception);
+        void DisplayConnectionMessage(ConnectionException exception);
+        void DisplayAuthenticationMessage(AuthenticationException exception);
+    }
+}
diff --git a/Borepin/Borepin/View/ConnectionStateView.xaml b/Borepin/Borepin/View/ConnectionStateView.xaml
index 4e78667..600b0f7 100644
--- a/Borepin/Borepin/View/ConnectionStateView.xaml
+++ b/Borepin/Borepin/View/ConnectionStateView.xaml
@@ -6,8 +6,8 @@
              xmlns:resource_text="clr-namespace:Borepin.Resources.Text">
     <ContentView.Resources>
         <ResourceDictionary>
+            <converters:AllTrueBoolConverter x:Key="AllTrueBoolConverter"/>
             <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
-            <converters:ListNotEmptyConverter x:Key="ListNotEmptyConverter"/>
         </ResourceDictionary>
     </ContentView.Resources>
     <ContentView.Content>
@@ -15,12 +15,17 @@
             <StackLayout IsVisible="{Binding IsBusy}">
                 <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
             </StackLayout>
-            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
-                <StackLayout IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}">
-                    <Label Text="No Connection to Server"/>
-                    <Label Text="Connecting to Server ..." IsVisible="{Binding IsConnecting}"/>
-                    <Label Text="Please select a Server." IsVisible="{Binding IsConnecting, Converter={StaticResource InvertBoolConverter}}"/>
-                </StackLayout>
+
+            <StackLayout>
+                <StackLayout.IsVisible>
+                    <MultiBinding Converter="{StaticResource AllTrueBoolConverter}">
+                        <Binding Path="IsBusy" Converter="{StaticResource InvertBoolConverter}"/>
+                        <Binding Path="IsConnected" Converter="{StaticResource InvertBoolConverter}"/>
+                    </MultiBinding>
+                </StackLayout.IsVisible>
+                <Label Text="{x:Static resource_text:TextResource.ConnectionStatus_NoConnection}"/>
+                <Label Text="{x:Static resource_text:TextResource.ConnectionStatus_Connecting}" IsVisible="{Binding IsConnecting}"/>
+                <Label Text="{x:Static resource_text:TextResource.ConnectionStatus_NotConnected}" IsVisible="{Binding IsConnecting, Converter={StaticResource InvertBoolConverter}}"/>
             </StackLayout>
         </StackLayout>
     </ContentView.Content>
diff --git a/FabAccessAPI/API.cs b/FabAccessAPI/API.cs
index 3bf0bbf..3c81f40 100644
--- a/FabAccessAPI/API.cs
+++ b/FabAccessAPI/API.cs
@@ -291,26 +291,19 @@ namespace FabAccessAPI
         /// <exception cref="ConnectionException"> When API-Service can not connect to a server </exception>
         public async Task<ServerData> TryToConnect(ConnectionData connectionData, TcpRpcClient tcpRpcClient = null)
         {
-            try
+            if (tcpRpcClient == null)
             {
-                if (tcpRpcClient == null)
-                {
-                    tcpRpcClient = new TcpRpcClient();
-                }
-
-                await _ConnectAsync(tcpRpcClient, connectionData).ConfigureAwait(false);
-                IBootstrap bootstrap = tcpRpcClient.GetMain<IBootstrap>();
-
-                ServerData serverData = await _GetServerData(bootstrap).ConfigureAwait(false);
-
-                tcpRpcClient.Dispose();
-
-                return serverData;
-            }
-            catch(System.Exception ex)
-            {
-                throw new ConnectionException("Test Connection Failed", ex);
+                tcpRpcClient = new TcpRpcClient();
             }
+
+            await _ConnectAsync(tcpRpcClient, connectionData).ConfigureAwait(false);
+            IBootstrap bootstrap = tcpRpcClient.GetMain<IBootstrap>();
+
+            ServerData serverData = await _GetServerData(bootstrap).ConfigureAwait(false);
+
+            tcpRpcClient.Dispose();
+
+            return serverData;
         }
 
         /// <summary>
@@ -357,7 +350,7 @@ namespace FabAccessAPI
                     sslStream.AuthenticateAsClient("bffhd");
                     return sslStream;
                 }
-                catch (AuthenticationException exception)
+                catch (System.Security.Authentication.AuthenticationException exception)
                 {
                     sslStream.Close();
                     Log.Warn(exception);