I also had this problem. I didn't even try the laughable suggestions from @Cass0317 . No "expert", hahaha. You know it is not a resolution issue or a hardware system requirement issue because the the program loads.
My First thought was the latest update had a bug that didn't like something on/in my system. I also removed Turbo Tax 2020 and installed again from my installer file created from the CD. I figured a fresh install without updating could work. Nope, you don't have the option to not update. I also flaunted the idea that it had issue was part of the recent massive update of Windows 10 (going to version 20H2). If this was the case, I am sure there would be way more heat on the program now working, so I didn't touch my current Windows 10 settings. Removing the program and installing fresh a) did not fix the issue and b) will use one of the five activation codes each purchase is allotted.
The populated window with moving blue dots suggest a hang in the authentication per the window title and not a hardware or system setting issue. There is a communication issue between your system and the Intuit Turbo Tax Servers. @danyank7 I like that realized this and you changed your firewall and network. That is the correct line of thinking. Have you a VPN? Perhaps on your computer or built into your router? Turning that off just long enough to get the Intuit Turbo Tax server to accept connection from your computer and authenticate. Then you can turn that VPN back on and enjoy some privacy. Took me fifteen minutes to remember my VPN. Be sure you turn your firewall back on. Shout if this doesn't work.
