After I started up my computer, having updated the last time I used it, going past the log in screen just shows the lock-screen background for a little bit, before a black screen with just a cursor. The Lock Screen still works if I shut the laptop lid or leave the computer enough, but the screen doesn’t seem to turn off properly when shutting the lid and most keyboard shortcuts don’t work, though I can still go to tty.
I tried updating. I tried reinstalling Cinnamon. That didn’t work, but installing lxde and selecting that at login worked, but Cinnamon still doesn’t.
I eventually found out that right clicking the black screen Cinnamon desktop still works, and I can get windows such as the terminal like that, but the windows won’t move or resize.
Probably just going to do a new install.
You can try to start Cinnamon on TTY to see what goes wrong.
Go to a TTY by pressing Ctrl + Alt + F3. Replace F3 with F4, F5, F6 etc if you are already on that TTY. Once you are in TTY, login with your user and its password. Then run cinnamon --replace. If it runs without any problems, the problem might be related to your display manager. If it doesn’t start, you should see the errors.