diff --git a/src/main/java/org/gcube/portlets/user/td/client/TabularDataController.java b/src/main/java/org/gcube/portlets/user/td/client/TabularDataController.java
index 623c18b..0081d00 100644
--- a/src/main/java/org/gcube/portlets/user/td/client/TabularDataController.java
+++ b/src/main/java/org/gcube/portlets/user/td/client/TabularDataController.java
@@ -347,9 +347,19 @@ public class TabularDataController {
 				new AsyncCallback<TRId>() {
 
 					public void onFailure(Throwable caught) {
-						UtilsGXT3.alert("Error",
-								caught.getLocalizedMessage());
-				
+						if (caught instanceof TDGWTSessionExpiredException) {
+							eventBus.fireEvent(new SessionExpiredEvent(
+									SessionExpiredType.EXPIREDONSERVER));
+						} else {
+							if (caught instanceof TDGWTIsLockedException) {
+								Log.error(caught.getLocalizedMessage());
+								UtilsGXT3.alert("Error Locked",
+										caught.getLocalizedMessage());
+							} else {
+								UtilsGXT3.alert("Error",
+										caught.getLocalizedMessage());
+							}
+						}
 					}
 
 					public void onSuccess(TRId trId) {