Hi there, AARDWOLF1. 

Lately, there was a report regarding the error message popping up when attempting to pay through bank transfer. However, the case is now resolved and closed.  

Let's isolate this case by performing browser troubleshooting steps to verify if this is the scenario. There are times that the browser stores frequently-accessed data, thus causing some errors or unusual behavior.   

Let's go ahead logging in to your QuickBooks Online account using a private or a different browser. Here's how: 

• Google Chrome: press Ctrl + Shift + N 
• Mozilla Firefox: press Ctrl + Shift + P
• Safari: press Command + Shift + N 
• Microsoft Edge: press Ctrl + Shift + P      

Once logged in, go back to the transaction you're trying to pay. If it works, it means that you need to clear the browser's cache so the system can start fresh. 

In another way, you can also do this task on other supported, up-to-date browsers. It could be the one you're currently working on has a temporary problem with QuickBooks.   

Fill me in if you have additional questions in QuickBooks. I'll be around to help. Stay safe!