I installed Pro Series 2020 this week and when I try to log in I get an error message "Bad Request". I tried deleting and reinstalling, tried  to install with a disable Norton antivirus, tried opening windows in safe mode, tried the entire process on two different computers, tried disabling my VPN. None of these work. I have been using Pro Series without any problems for 20 years. 

I called customer service and they insist it isnt the software and it has to be my computer. 

I'm running Windows 10 on a stand alone basis. 

Any ideas?