I was running the latest Firefox version also on my WIN10 machine. I was trying to register on AT&T forums. Every time I tried to register using my Firefox browser, I got an error message, something like 'Error, please try again later'. I wasted SO MUCH TIME WITH FIREFOX, trying to register on the AT&T forums. ARRGH! So I decided to try another browser. My very first attempt to register using the WIN10 built-in MS Edge browser worked perfectly. The puzzle picture test appeared to confirm I was a real user. I clicked on the correct squares and my registration went thru immediately. WHY DID THIS HAPPEN? Now I am wondering how many other sites have I had trouble with, just because of FIREFOX?