diff --git a/mindplot/src/main/resources/messages_en.properties b/mindplot/src/main/resources/messages_en.properties
index c18c7719..064791f1 100644
--- a/mindplot/src/main/resources/messages_en.properties
+++ b/mindplot/src/main/resources/messages_en.properties
@@ -57,4 +57,5 @@ CANCEL=Cancel
 LINK=Link
 OPEN_LINK=Open URL
 SESSION_EXPIRED=Your session has expired, please log-in again.
+URL_ERROR=URL not valid