diff --git a/docs-android/app/src/main/java/com/sismics/docs/activity/DocumentViewActivity.java b/docs-android/app/src/main/java/com/sismics/docs/activity/DocumentViewActivity.java
index 06297596..b586a911 100644
--- a/docs-android/app/src/main/java/com/sismics/docs/activity/DocumentViewActivity.java
+++ b/docs-android/app/src/main/java/com/sismics/docs/activity/DocumentViewActivity.java
@@ -76,11 +76,6 @@ public class DocumentViewActivity extends AppCompatActivity {
      */
     public static final int REQUEST_CODE_ADD_FILE = 1;
 
-    /**
-     * Request code of editing document.
-     */
-    public static final int REQUEST_CODE_EDIT_DOCUMENT = 2;
-
     /**
      * File view pager.
      */
@@ -214,7 +209,7 @@ public class DocumentViewActivity extends AppCompatActivity {
             public void onClick(View view) {
                 Intent intent = new Intent(DocumentViewActivity.this, DocumentEditActivity.class);
                 intent.putExtra("document", DocumentViewActivity.this.document.toString());
-                startActivityForResult(intent, REQUEST_CODE_EDIT_DOCUMENT);
+                startActivity(intent);
             }
         });
 
diff --git a/docs-android/app/src/main/java/com/sismics/docs/util/NetworkUtil.java b/docs-android/app/src/main/java/com/sismics/docs/util/NetworkUtil.java
index a81b4862..fb5959a4 100644
--- a/docs-android/app/src/main/java/com/sismics/docs/util/NetworkUtil.java
+++ b/docs-android/app/src/main/java/com/sismics/docs/util/NetworkUtil.java
@@ -1,9 +1,14 @@
 package com.sismics.docs.util;
 
+import android.Manifest;
+import android.app.Activity;
 import android.app.DownloadManager;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Environment;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
 
 /**
  * Utility class for network actions.
@@ -19,9 +24,14 @@ public class NetworkUtil {
      * @param title Notification title
      * @param description Notification description
      */
-    public static void downloadFile(Context context, String url, String fileName, String title, String description) {
-        String authToken = PreferenceUtil.getAuthToken(context);
-        DownloadManager downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
+    public static void downloadFile(Activity activity, String url, String fileName, String title, String description) {
+        if (ContextCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
+            ActivityCompat.requestPermissions(activity, new String[] { Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
+            return;
+        }
+
+        String authToken = PreferenceUtil.getAuthToken(activity);
+        DownloadManager downloadManager = (DownloadManager) activity.getSystemService(Context.DOWNLOAD_SERVICE);
         DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
         request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
         request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);