A file in the user's HOME System Folder appears to be corrupt. To correct, try these options:
1) In a shell, delete the ".fs_cache" file in the System Folder, the restart MAE.
2) If the above does not work, rename the user's System Folder, and launch MAE. This will force MAE to create a new system, and the user can then copy desired control panels and extensions from the previous System Folder to the new one.