Bitlocked "Windows 8 To Go" failed

[Hatan]

I've just tried "Windows To Go Upgrader" on a bitlocked version of "Windows 8 To Go", but after entering the Bitlocker-Key I was getting a blue screen. Do I first need to decrypt "Windows 8 To Go"? (Afterward "Windows 8 To Goo" hardly booted up again ....)