Thank you for visiting the QuickBooks Community again, 545585935. I can see how urgent it is to change the scheduled date or void the transaction from the online bill payment. With this, I'll be sharing information about this matter and pointing you to the right support team to assist you further on this issue.
Getting a blank screen when clicking Bill Payment or Pay Bills Online has been recently tagged as an ongoing issue. Our product engineers are now working to fix this as soon as possible. For now, we're unable to provide an exact workaround to be performed.
I suggest contacting our QuickBooks Online Support Team, so they can add you to our notification list. This will help our engineers determine the number of affected users. You'll also receive an update through email once this has been resolved.
Lastly, you may refer to this article to see the different features and benefits of using Online Bill Pay: What is Online Bill Pay?.
I'm just one click away if you need anything else about Online Bill Payment and running your business in QBO. I'm always around to help, 545585935. Have a good day!