I'm using Dominion 1.6 Gantry 1.29 and WordPress 3.5
After I updated the theme, gantry and wordpress my all gantry settings were lost. Luckily I was able to restore from a backup.
Then I went on attempting to make some updates, add aditional widgets and change the layout. At first I thought that only the widget panel for Overrides was broken. Somehow I managed to fix this, I fiddled with everything for a few days and finally got the widgets to work again.
Then I went to change the layout of a section and found that this tab was broken as well.
Then I thought, oh to hell with this theme, I'll try another. But any other rocket theme I tried to use would only bring up a white screen with:
I tried creating another test site from scratch (twice) and it didn't matter. I had the same problem.