Well this isn’t good. I can’t seem to login to my computer this morning. It reboots fine. I get to the login screen, but when I put in my password the progress bar moves ahead a few pixels and then just stops. The computer freezes solid. So solid there’s no mouse, caps lock doesn’t toggle, and the time stops updating.

Tried safe mode which didn’t work either.

Well, I don’t really know what to do. If I knew more about the internals I could probably fix whatever is wrong in recovery mode Terminal, but I kinda don’t.

I can get in Recovery Mode just fine. I ran Disk Utilities repair stuff on all the volumes. There were warnings about things not being the expected size. I ran it again, they were all gone.

Reboot - same effect.

I have a second user account on this machine that was setup for testing so its the most basic user account (not startup things) and it does the exact same thing - gets maybe 1/10th of the way on the progress bar and the whole entire computer locks up.

In Recovery Mode Terminal I got a list of APFS snapshots on my Data volume and there were a lot. So I painstakingly deleted every one of them using terminal commands (couldn’t get the tmutil to work - it complained about frameworks and dylibs).

Sadly that didn’t fix it either.
@bigzaphod Data volume corruption.