diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index f61aa40..17a5b85 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -2705,6 +2705,9 @@ class assign {
         $modifiedusers = array();
         foreach ($currentgrades as $current) {
             $modified = $users[(int)$current->userid];
+            if ($modified->lastmodified < 0) {
+               continue;
+           }
             $grade = $this->get_user_grade($modified->userid, false);

             // check to see if the outcomes were modified