I've tried searching both the forums and google for this error message, and found nothing, except a post in a german forum by someone with the same problem, but no solution that I could see. I don't speak german, so I think it's alright to ask here instead.
I'm trying to set up guest session on a fresh install of Linux Mint 20 "Ulyana" - MATE (64-bit). I've flipped the switch for "Allow guest sessions" in "Login Window > Users" and rebooted. But when I try to login to the guest session I get the following error message:
There doesn't seem to be any such file, and the only folder in /run/user/ is "1000".Could not update ICEauthority file /run/user/999/ICEauthority
Does anybody with more experience know what could be causing this?
Most results I've found for other "Could not update ICEauthority file" errors seem to be about an ICEauthority file in the user's home folder with the wrong permissions, but in my case the file can't have wrong permissions as it doesn't exist. I've tried creating the file, but on reboot both it and the folder are gone again. Maybe the problem is not in this file, but in why this folder doesn't exist at all? Should it have been generated when I activated "Allow guest sessions"? Or is this a folder that used to be "999" in earlier versions, but is now "1000", and some references to this have not been updated?