I decided to enable full disk encryption using FileVault2 in OSX Mountain Lion, but near the end of the encryption process, I get a message telling me that it failed, and that I should disable and reenable it to try again. When I try to disable it I get an error: An error occurred while reverting the disk. (Error: -69755). So I am stuck in a vicious cycle. Luckily, the drive is still accessible and usable, but it's clearly not encrypted.
Here are screenshots of the process:
I would prefer to avoid reformatting the drive (it's a single partition).
There is a long thread in the Apple Support Communities, but there is no acceptable answer so far. https://discussions.apple.com/thread/4218952?start=0&tstart=0