I have a beforeLoad button added to a PO, the user click that button and it take the user to a Suitelet to confirm the PO Date, once the date is confirmed the ClientScript on that Suitelet show a message and redirect the user back to the PO using document.location = url. Once the user is back on the PO record if the user click the Button again the page hand for a few seconds and the console show a bunch of error... see image below...