diff --git a/seahub/api2/views.py b/seahub/api2/views.py
index 34b1ffc21f..c24e0b4799 100644
--- a/seahub/api2/views.py
+++ b/seahub/api2/views.py
@@ -292,10 +292,15 @@ class Account(APIView):
         copy['email'] = email
         serializer = AccountSerializer(data=copy)
         if serializer.is_valid():
-            user = User.objects.create_user(serializer.object['email'],
-                                            serializer.object['password'],
-                                            serializer.object['is_staff'],
-                                            serializer.object['is_active'])
+            try:
+                user = User.objects.create_user(serializer.object['email'],
+                                                serializer.object['password'],
+                                                serializer.object['is_staff'],
+                                                serializer.object['is_active'])
+            except User.DoesNotExist as e:
+                logger.error(e)
+                return api_error(status.HTTP_403_FORBIDDEN,
+                                 'Fail to add user.')
 
             self._update_account_profile(request, user.username)
 
@@ -332,7 +337,11 @@ class Account(APIView):
         if is_active is not None:
             user.is_active = is_active
 
-        user.save()
+        result_code = user.save()
+        if result_code == -1:
+            return api_error(status.HTTP_403_FORBIDDEN,
+                             'Fail to update user.')
+
         self._update_account_profile(request, user.username)
 
         try:
diff --git a/seahub/base/accounts.py b/seahub/base/accounts.py
index 88ffcd8411..d04cab0a17 100644
--- a/seahub/base/accounts.py
+++ b/seahub/base/accounts.py
@@ -160,15 +160,18 @@ class User(object):
             else:
                 source = "LDAP"
 
-            ccnet_threaded_rpc.update_emailuser(source,
-                                                emailuser.id,
-                                                self.password,
-                                                int(self.is_staff),
-                                                int(self.is_active))
+            result_code = ccnet_threaded_rpc.update_emailuser(source,
+                                                              emailuser.id,
+                                                              self.password,
+                                                              int(self.is_staff),
+                                                              int(self.is_active))
         else:
-            ccnet_threaded_rpc.add_emailuser(self.username, self.password,
-                                             int(self.is_staff),
-                                             int(self.is_active))
+            result_code = ccnet_threaded_rpc.add_emailuser(self.username,
+                                                           self.password,
+                                                           int(self.is_staff),
+                                                           int(self.is_active))
+        # -1 stands for failed; 0 stands for success
+        return result_code
 
     def delete(self):
         """
diff --git a/seahub/views/sysadmin.py b/seahub/views/sysadmin.py
index 55774b5aae..ddda76d2a4 100644
--- a/seahub/views/sysadmin.py
+++ b/seahub/views/sysadmin.py
@@ -867,7 +867,10 @@ def user_toggle_status(request, email):
     try:
         user = User.objects.get(email)
         user.is_active = bool(user_status)
-        user.save()
+        result_code = user.save()
+        if result_code == -1:
+            return HttpResponse(json.dumps({'success': False}), status=403,
+                                content_type=content_type)
 
         if user.is_active is True:
             try: