Q: Filevault 2 does not start with encryption

Don't bother with Filevault, you have to give up the password to have your computer fixed and to law enforcement, Customs etc., also it's cracked using third party software.

If you have data you don't want anyone to see, use a external self encrypting Iron Key or self encrypting (hardware based encryption) external powered drive with keypad/key, that way you can use it with any computer.

Is this a factory-installed SSD or an aftermarket one? Some aftermarket SSD's are not fully compatible with Macs.

If you are potentially the target of a sophisticated and highly motivated attack, read the following:

Firewire Attacks Against Mac OS Lion FileVault 2 Encryption

I don't mean that this is an attack. I mean that there are steps you can take to make FileVault more secure, once it's working.

Launch the Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad. Click Utilities, then Terminal in the page that opens.

Drag or copy — do not type — the following line into the Terminal window, then press return:

diskutil list

Post any lines of output that appear below what you entered — the text, please, not a screenshot.

If any personal information appears in the output, edit before posting, but don’t remove the context.

Check the App Store to make sure no firmware update is available for your model.

If the firmware is up to date, use Recovery Disk Assistant to make a bootable recovery device.

Back up all data to at least two different storage devices.

Boot from the recovery device and launch Disk Utility. Partition the internal drive with the default options (one data partition.) Install OS X (you will need your Apple ID and password, so make a note of them before you begin.) Reboot and restore your data from a backup in Setup Assistant. Try again to activate FileVault.

Hi, did you got any result?

I have the same problem.

I can not activate FileVault2 on my MBA (late 2011, OSX 10.8 (updatet from OSX 10.7)).

I get the same fault MSG.

Brgds Peter

same here! I also would like to know if a complete wipe of the drive and restoring everything is the only solution to the problem!

I get the same message. I wiped my hd several times restoring with the migration assistent or time machine. It all did not help. Today I installed the update 10.8.1 hoping this might hepl. The installation process ended with an error message. After reboot the system information showed, that despite the error message the system was updated to 10.8.1. I hoped filevault would work after this, but it doesn't. Still the same problem. Any solutions?

@ajberlin

Did you wipe the drive and then restore everything (including the OS) from a backup? If the problem is some already existing or corrupted system file, this wouldn't work because you would restore the same file again from your backup. The only solution that (probably) works as Linc Davis pointed out above is wiping the drive after booting from an external drive, installing Mountain Lion freshly again from the external drive and then restoring your data (but not the system!) from a backup.

Can somebody confirm that this indeed solves the problem?

I had the same issue/same error message with a 3rd-party SSD. Solution was to install Lion, encrypt the disk with 10.7, update to 10.8 and restore from Time Machine. Very time-consuming. I think there is some kind of FileVault2 bug in Mountain Lion, because the encryption worked with 10.7 on the very same disk.

I wiped the whole disk, installed the OS again and restored the data not with time machine, but with the migration assistant. This also did not help.