Session handling to prevent session lose in other places like, home, admin, etc

when user is using the new designer that have not session because it is using only the API

workflow/engine/classes/model/om/BaseAppNotes.php

@@ -287,6 +287,10 @@ abstract class BaseAppNotes extends BaseObject implements Persistent
 
         if ($v !== null && !is_int($v)) {
             $ts = strtotime($v);
+            //Date/time accepts null values
+            if ($v == '') {
+                $ts = null;
+            }
             if ($ts === -1 || $ts === false) {
                 throw new PropelException("Unable to parse date/time value for [note_date] from input: " .
                     var_export($v, true));