Index: /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/client/app/modules/administrator/userMgmt/modal/user.add.controller.js
===================================================================
--- /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/client/app/modules/administrator/userMgmt/modal/user.add.controller.js	(revision 2412)
+++ /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/client/app/modules/administrator/userMgmt/modal/user.add.controller.js	(working copy)
@@ -128,7 +128,12 @@
                         } else {
                             if (response.data[2] && angular.isArray(response.data[2])
                                 && response.data[2].length === 1 && response.data[2][0].length === 2) {
-                                addViewModal.errorMsg = $filter("T")(response.data[2][0][1]);
+                                let errorMsg = $filter("T")(response.data[2][0][1]);
+                                if (errorMsg === 'This instance is already existed.') {
+                                    addViewModal.errorMsg = 'Username already exists.';
+                                } else {
+                                    addViewModal.errorMsg = errorMsg;
+                                }
                             } else {
                                 $uibModalInstance.close(true);
                             }
Index: /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/cm/models/system/user_mgmt/__init__.py
===================================================================
--- /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/cm/models/system/user_mgmt/__init__.py	(revision 2412)
+++ /branches/amp_3_7_0/src/webui/webui/htdocs/new/src/cm/models/system/user_mgmt/__init__.py	(working copy)
@@ -67,6 +67,7 @@
                 self._model._meta.mark_delay_query(data)
             return QuerySet(self._model, result_name)
 
+        # ToDO: Bug-1022 - Fix should be from the backend for errors & exceptions, revamp hive/manager.py to handle the exceptions & error responses better.
         def _insert(self, instance):
             data = instance.get_field_dict()
             session = self._session