Update as of February 28, 2021:
This week I installed the latest Big Sur update 11.2.2 (on my iMac). Prior to installing this update, I followed the steps listed in another Turbo Tax Community posting that recommended you delete a series of folders in you ~Library.
After the Big Sur update to 11.2.2, I re-installed Turbo Tax and it is now working properly. I'm relieved to have the program functional again. I hope those that have been having problems with TT and Big Sur can get resolution and finish up their taxes.
