Well, instead I went to Microsoft Edge and got the true error that was occurring. However, I do not know who is responsible for the bad message so I will let Firefox know what happened in Microsoft Edge. It was a pop-up window at https://www.mysynchrony.com/ that put up a form, but I was entering the wrong data and the error message (which appeared at the top of the pop-up window upon submitting the form) was that the router number and account number were not verifiable at that bank. Which was true as I was entering the wrong account number. Once I entered the appropriate account number, the form processed with no problems. Basically, because of the error message being incorrect, I was getting aggravated over a simple process because I was looking across the street for an error in my own back yard. The error message that shows here is not even close to what was actually occurring as it reads as a time-out error and that is not the case, there is a legitimate data error behind submitting the form. I will inform Synchrony, however, I do not know what their stance on Firefox is. I do check any issue within Firefox against Microsoft Edge, because some companies do not update Firefox quickly and/or they have chosen to not make their websites compatible with Firefox. Firefox is number one to me, but not everyone agrees. I dislike Google chrome so this is the way of the world.

You normally get the error that the document has expired if you try to go back to a page that you aren't supposed to go to.

Do you use a bookmark or are you starting with the main (home) page of this website?

If you use a bookmark to access a specific page then instead navigate to this page starting with the main page or with the sign in page in case there is a problem with this bookmark.