I've been running 12.04 (64-bit) for quiet a while now without any major problems. But when trying to login in today, the GUI failed to come on and was stuck at a flashing cursor. I switched to a console (CTRL–ALT–F1) to see what the problem is. Looking in /var/log/Xorg.0.log I get the following failure line:
(EE) Screen(s) found, but none have a usable configuration
I thought it might be something to do with Nvidia drivers so I did a purge of the nvidia stuff (sudo apt-get purge nvidia*) and reverted the xorg.conf file to the little failsafe one that uses vesa. But this still comes up with the same error, so I doesn't look like it's the nvidia stuff that's causing the problem.
I'm really stumped now, any ideas? I assume the last update has changed something, but I'm not sure what was updated that could have caused this.
Best Answer
I could solve it reconfiguring the GUI by executing:
and restarting. In my case it recovered the previous (correct configuration).