Does Windows get a "blue screen" error? In that case, I would think a part of your hard drive or SSD has gone bad, and would suggest some kind of disk utility to clean things up.

However, Windows shutting down like you told it to shut down, sounds a bit malware-ish. You might want to try running some malware cleaning software, but you might need to restart Windows in its "Safe Mode with Networking" to do that, depending on the situation. This support article recommends free (or free trial) programs other Firefox users have found helpful:

Troubleshoot Firefox issues caused by malware

No, just totally shutdown, as in turned itself completely off, and only when I typed that or searched for sessionstore-backups. I don't have a clue how to do safe mode with networking but I can try a malware cleaning first before I go that route. Would malware have caused the locking up problem also, maybe?

Can you open Windows File Explorer and browse that way to "AppData\Roaming\" or "AppData\Roaming\Mozilla\" ?

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• https://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• https://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

As much as I hate to admit this, the shutting down problem was operator error, I kept pushing the shutdown button to make the computer search. I'm going to blame being sick here (currently dealing with a potassium deficiency from being sick and my brain isn't working), and maybe without my computer for a week, too. So very sorry for the problem. On the plus side, I did two different malware searches to make sure and there do not seem to be any nasties making my computer sick at least. Thank you so much for the help on this and will get back to figuring out the other problem, lol. And for suggesting the malware search!