During a transaction, randomly POS will crash on the register saying "An unhandled expection has occured. The program can't continue and needs to shut down. Looking at the exception information, the following is listed: An exception of TypeSystem.NullReferenceException has occurred. Exception message: object reference not set to an instance of an object". Not only is this a problem, but the current transaction cancels and we can not reprint a receipt. It removes the item from inventory, but we can't find the transaction. Help!!