in file: \administrator\components\com_virtuemart\views\orders\tmpl\order_print.php
line 210:
$returnValues = $dispatcher->trigger('plgVmonShowOrderPrintPayment', array($this->orderNumber, $this->virtuemart_shipmentmethod_id));
'plgVmonShowOrderPrintPayment' change to 'plgVmonShowOrderPrintShipment'