LM MATE 17.1 Cybertron Custom 4000 Dual boot w/ WinXP for a few apps.
I was adding a second panel when the screen froze with only the wallpaper and movable cursor. Oh, and a slightly "jiggly" workplace switcher, also inop.
Nothing else works- can't click on anything, can't raise a terminal, no nothing.
I did a second install of same 17.1 and can go through Menu's "Computer" to get to the entire frozen install, files and all and everything works.
Have tried hard shutdowns. Rebooted with plain starts, optional fix-it starts, and searched the web high and low for a similar situation all to no avail. Seems that all I need is a way to unlock the desktop.
Currently doing this on the second bare-bones install.

I posted a reply about this on Twitter and debated to post it here since it's really hard to tell what the issue is with the provided details, but the only times I have been locked out of *nix desktops it has been because of a corrupted .Xauthority file (corrupted or owner taken over by root). If you can access a terminal (or ext2fs in Windows) and your HOME directory you can just: or set the owner to you, but deleting the file should not hurt anything.

I've had similar freezes occur, though very rarely.

My course of action is to press ALT-CTRL-F2 to go to another terminal, log in as root, and issue the reboot command.

(I've found that, if I subsequently press ALT-CTRL-F1 to return to the first terminal, X is normally shutting down.)

I would like to add a +1 to this.

I'm running Mint Cinnamon 19.2 with all updates installed to date. Everything seems fine until the system freezes.

Sometimes the mouse still works to move the pointer, sometimes not. I believe it is happening in the browser (tried Firefox, Chrome and Chromium all with similar results) but I couldn't swear it's never happened in other apps.

I've tried reverting to older kernels without success.

I'm pretty confident in the hardware (Ryzen 5 3600) because I can run Windows 10 for weeks without any failure, Linux rarely will go more than an hour without locking up.

Just for fun I've also run it on Manjaro 18.1, no joy there either, in fact it's worse.

So does anybody have any ideas?

What I'd really like to have is a ctrl-alt-delete type of emergency escape so I can get out without rebooting and maybe gain some info on what might be happening. I really feel that this is a shortcoming that if there is a freeze there's no way out except rebooting.

Ideas?

TF