I ended up uninstalling and reinstalling but was still unable to load my 2019 file to begin 2020 return. The system also says it would read pdf versions, but that bombed as well. Ended up doing 2020 from scratch.
HOWEVER...
Not only did I do multiple saves while working on 2020 data, I also left the file name alone (default) thinking maybe that was somehow related to the problem with my prior year's file (which name I customized when saving). Before going too far with 2020 data, I saved my file and ended the program, then reopened the current year file without problem. I was also able to bring in the 2019 files to just set up the 2020 returns for my family members (they were saved using 2019 file name defaults), resaved them to my 2020 hard drive folder using their default names, and haven't had any other issues reaccesing them.
Take this for what it's worth. Still shouldn't have had the issue with my saved 2019 file, but...
