Problem in Tickets with 5.3.0 - by: magast

After updating to 5.3.0 it is not possible to create a new ticket.

2016-03-29 15:38:31.400 ***** ERROR ***** ERROR *****
2016-03-29 15:38:31.400 ***** ERROR ***** on file '/var/www/apps/w2u/projectorria/model/TicketMain.php' at line (336)
2016-03-29 15:38:31.400 ***** ERROR ***** cause = Undefined property: Activity::$idTargetVersion

The error appears only if i want to add a activity to the ticket.

Solved wich additional code in line 336 like:
if (isset($act->idTargetVersion) && $act->idTargetVersion) { ...