Third party apps all hang
I woke my MacBook (Retina, 12", 2007 running 10.15.7) from sleep this morning, and I was getting the error that I had to sign in to my AppleID again for some services to work (which, were not specified). So I opened the AppleID system preference, then tried to open 1Password to retrieve my AppleID.
First, I noticed that the LaunchBar app wasn't working, so I went to the Applications folder and ran LB; while there, I launched 1Password. Neither opened. No errors, they just wouldn't seem to launch.
I thought maybe something had hung, so I restarted the MacBook. It didn't seem to work: quite some time went by and no restart. So I forced a shutdown via the power button and then restarted.
Reboot seemed slow--the signin screen came very quickly, but the final 5-10% of the boot process bar took longer than normal (or seemed to). Then everything seemed OK but no third party applications would open; Safari and Mail opened normally, but Malwarebytes and BitDefender (I wanted to check for malware) would not, or any other non-Apple application I tried.
I rebooted in Recovery mode; it seemed slow to check for drives, but I can't recall when I last needed Recovery mode so maybe that's normal. Ran Disk Utility via Recovery and no errors found on either volume. FWIW, DU reported that the internal drive is "shared by 5 volumes" and displays two (Macintosh HD and MacintoshHD - Data); I never myself partitioned the drive, and might have expected two, with OS X having created a Repair drive, but no volume named "Repair." The side panel in DU shows:
Apple SSD AP0512J Media
> Container disk1
>>Macintosh HD
>>Macintosh HD - Data
Restarted and same problem remains. FWIW, I don't get the AppleID-signin alert anymore (everything in System Preferences seems normal). I tried to launch Malwarebytes and BitDefender again, but they don't appear in the applications switcher, or in Activity Monitor. 1Password, which is part of login items, does appear in Activity Monitor but I can't switch to it and it doesn't seem to open when I run it from Finder.
When I tried to restart/shut down it was a SLOW process, and reported that certain 3rd party applications interrupted restart by failing to quit; these seem to be login items. I have to force quit them one at a time (as they are reported) from Activity Monitor and the MacBook restarted.
Restarted in Safe mode. Still couldn't get any 3rd party applications to launch. I shut down, and again it was slow--this time it was FrontendAgent that wouldn't quit, presumably from when I'd tried to run Malwarebytes. Forced-quit that (no login items had launched so that was all) and the MacBook shut down immediately and restarted, back in its "regular" state, with no non-Apple apps able to run, but even things like TextEdit launching.
What's going on? Am I just going to have to restore from Time Machine?