I ran the following to change my users UID & GIDs - but, now I have no
graphic gdm login. I have no problem with a terminal login and the
same worked on a terminal based server.
Check your logs with journalctl.
There is also ~/.xsession-errors, but you probably lost access to your own home dir.
As root do:
$ chown -R joe /home/joe
and login as joe
Create another user and try login with it. Does it work?
If it doesn't work:
Make sure that ``/tmp`` folder has full write permissions of everyone.
If not, fix it
Disable graphical login i.e. (``systemctl set-default multi-user.target``) and reboot.
Try to start x with ``startx`` from the console.
Does it work? If not, check /var/log/Xorg.* log