I have been using the desktip version of turbo tax since 1995 (no kidding!) and I've never run into the problem being described here. Also, I have had a process of backing up my hard drive using various methods as things evolved since 1993!
When you are using a laptop / PC unfortunately you are your own IT department.
Even if you turn off the automatic updates, you still have to manually update the software to file. if the root cause is the Turbo Tax downloads, turning off the the automated download will not prevent the problem as the manual download may cause the same damage. And the only difference between automated and manual in my view is when it occurs - the files that are downloaded and manipulated might be the same.
the real solution is backing up the hard drive!!!
ps - here is an idea before all is lost....using file explorer, manually change the extension on each of the *.scd files to .tax2021. it may be the file itself wasn't damaged but the extension was the only thing changed.
