If you have 2019 software installed, recommend try
-disconnect your PC from internet and wifi, ie isolate it.
-set time and date to sometime in 2020-2021.
-do NOT update - when asked, decline to update. An my case, everything appeared to work until I was asked to update my software. At the time I had current time on my PC
To access 2018 TT and earlier, I make sure to isolate my PC, set the time within the 3 yr window, do not update the software.
FYI, not all DIY software have sunset dates, but apparently all TurboTax software now does - information that would have been useful before the sunset date occurred. When is the sunset date for Turbotax 2020? 2021? Also FYI, I did end up using IRS paper forms for 2019 doing the calcs in a spreadsheet.
