diff --git a/workflow/engine/classes/model/AppNotes.php b/workflow/engine/classes/model/AppNotes.php
index 69b83aaf3..012162e86 100755
--- a/workflow/engine/classes/model/AppNotes.php
+++ b/workflow/engine/classes/model/AppNotes.php
@@ -254,7 +254,9 @@ class AppNotes extends BaseAppNotes
             $noteRecipientsList = array();
 
             foreach ($p["array"] as $key => $userParticipated) {
-                $noteRecipientsList[] = $key;
+                if ($key != '') {
+                    $noteRecipientsList[] = $key;
+                }
             }
 
             $noteRecipients = implode(",", $noteRecipientsList);