Unity suddenly not starting for user

[r0t]

All of a sudden, Unity does not start when logging in. I have only a desktop, no dash, no panels, nothing else. The problem is limited to one user account.

Doing ctrl-alt-F1, and running export DISPLAY=:0 and compiz --replace does restore dash (but not panel) for the current session only.

This is what I tried so far, without any success:

* removing ./config/compiz-1, reboot

* running ccsm and make sure all required plugins are enabled

* apt-get install --reinstall ubuntu-desktop, as well as unity

When trying

export DISPLAY=:0
dconf reset -f /org/compiz/
setsid unity

I get the following error:

[drm:intel_lvds_enable] *ERROR* timed out waiting for panel to power on

Any ideas about what to try next?

[CantankRus]

Can you boot to a previous kernel?

[r0t]

The problem, it seems was with lightdm. I still don't know what happened, but purging and reinstalling lightdm magically helped!