Solved: in file helper.php at line 81 replace

if ($order_by == 0) {

 $query .= " order by #__k2_items.publish_up $order_by_asc_desc ";

 }

with code

if ($order_by == 0) {

$query .= " order by #__k2_items." . $date_type . " $order_by_asc_desc ";

}