After logging in to my account, I see no panels or anything else, only the background. I cannot even start a terminal with ctrl+alt+t. The only thing the system responds to is ctrl+alt+delete which shows the system monitor (without the top panel) or ctrl+alt+F1 to login by hand. However logging in to the guest session works fine.
When logging in by hand I cannot restart unity (unity --replace), this gives me:
unknown job: unity-panel-service
Without the graphics display open I cannot reset compiz and unity to default settings. Searching other questions I tried to move the .Xauthority in ~/ to some other place. Did not work. I also tried the
sudo apt-get install --reinstall ubuntu-desktop and
sudo apt-get install --reinstall unity +rebooting. Also tried to reinstall
lightdm. Nothing works.
I've been running on Ubuntu 14.04 LTS just fine for quite some time and haven't recently done any changes besides installing updates.