Update: I called Support again, and the TTax support rep tried to help. He came up with what I thought was a brilliant idea: I should run TTax as Administrator. I really thought that was going to work. But, sadly, it didn't.
Today, I took it upon myself to Uninstall TurboTax; download again the TTax installation program; Run as Administrator the TTax installation program; Run as Administrator the newly installed TTax. It Updated just fine. But the exact same problem happens: The Desktop TurboTax requires me to Sign-In but it won't accept it and keeps asking for me to Sign-In.
Please keep in mind that obviously I have the proper Sign-In credentials because the TTax website had allowed me (after signing in) to download the install program again.
As always, if I'm ever able to run TurboTax, I will let y'all know.
