I recently installed latest Ubuntu 17.10 (studio flavor) on Thinkpad laptop. Have not installed anything on it yet, still, after several hours of working, now after I enter password on logon screen, I see line
/dev/sdb5/clean, ... flashing for a moment and get back logon screen.
Recovery mode says APT is ok, filesystems are ok. In CLI consoles I can login,
timeout in locking authority file /home/... and does not start GUI. I can however start X as root (
sudo startx). I tried to add new user - also cannot login in GUI.
I found maybe related: cannot-login-after-running-startx-and-rebooting, maybe I did run X as root, do not remember, however, doing
sudo rm .Xauthority did not help (I did the command as my user, not root).
What can be cause of that problem? I want to have stable working laptop and ready to investigate.