When I log out in Ubuntu using the GUI log out option, often the GUI interface disappears and I am left with a black screen or my desktop background and a movable mouse cursor. The system is still responsive; I can log in via TTY1 (CTRL+ALT+F1) and perform a safe shutdown however the GUI remains unresponsive.
I don't know what causes the problem but it doesn't happen all the time. Occasionally if the log out process completed and I am returned to the Ubuntu login screen, when I log back in I get a "System Problem Detected" notification and some mention of Xorg crashing.
A bit of background as to what I have done to likely stuff up my Ubuntu system:
- I attempted to install OS X on my PC (unsuccessfully) and so that I could access the OS X files from Ubuntu I followed the steps here to change my Ubuntu user ID. Unfortunately this made my user account partially unusable (didn't appear on login screen, Settings/User Accounts, etc) and Fingerprint-GUI stopped working.
- Reinstalling Fingerprint-GUI (including policykit-1-gnome) with no success; the fingerprint driver stopped working for some reason.
Also I have installed Bumblebee for NVIDIA Optimus compatibility and that works fine.
If possible, I would like to get the log off button to function correctly and actually log off.