I attempted to log into my account with my usual password. I have never changed it on this machine. It did not work. I tried my guest account as well and it also didn't work. I'm certain of both passwords and that they go to both users. It worked as recently as yesterday. I haven't knowingly changed anything about the accounts recently.
To debug, I accessed the root command line through the GRUB menu. I ran
to see all users and nothing was returned. This is strange to me, since all the users were still listed in the GUI login menu. I added a new user to test, giving it a simple password. When I rebooted, the new user was in the login menu, but still no luck logging in. What could be going on here? I would love to avoid reinstalling if possible.
Another potentially useful detail: When I type the correct password, the machine stops and thinks for a minute, goes black, as though about to log in, then returns to the login page with no error message. When I type the wrong password, it returns a "Invalid Password" message immediately.