Comment 21 for bug 861643

Thank you Adam and freethinker. That worked for me too on both machines. There were two key binding conflicts with the 'Static Application Switcher' and one with the 'Desktop Wall' plugin. Inconvenient but doable now that I know the magical incantation.

Basically we're following the instructions in Ask Ubuntu here: http://askubuntu.com/questions/63921/unity-3d-doesnt-work-anymore-just-shows-a-menu-on-the-top It turns out all you need to do is log out of your corrupted Unity (ctrl-alt-delete) and switch to Unity 2D and log into it. Then start CCSM and enable the Unity plugin. It will pop up a dialog about Ignore or Resolve conflicts. Choose Resolve conflicts and then select the middle button for each conflict. Then log out of Unity 2D choose Unity and log in to it. It should be back to normal.