--- lib/gradelib.php.orig	2015-08-14 17:04:49.700287420 +0200
+++ lib/gradelib.php.new	2015-08-18 14:00:19.027217287 +0200
@@ -1027,6 +1027,9 @@
         if ($course_item->needsupdate) {
             $updated_item->force_regrading();
             return array($course_item->id =>'Can not do fast regrading after updating of raw grades');
+        } else {
+            // nothing to do :-)
+            return true;
         }
 
     } else {