I had success and solved this. I ended up uninstalling and reinstalling. Here's what I experienced.
I had a very complicated return which I dreaded having to redo due to a failure of TT to apply an update. I finally solved this error after reading on this forum, how others uninstalled and reinstalled the orogram. I called in, and after a lot of back and forth regarding remedies I tried unsuccessfully, I was instructed to delete and reinstall the orogram.
As a precaution, I first located my my tax file in Windows 10, and saved it in 2 places. I did another manual hard backup of my entire computer. I then uninstalled and reinstalled Turbotax.
Next, I opened the program, registered it (again) and allowed it to do it's standard update. Next, I initiated a New Return, and the program immediately located and opened my old file! It went seamlessly after that and I efiled quite easily.
