If you are seeing this message, it is possible that you just don't have sufficient rights to read a certain registry key. This issue has been reported on a Windows 7 64bit box. To fix it, either run Visual Studio (or your test runner) as an admin, or relax the permissions for the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\TypeMock\TypeMock.NET\Packs\Ivonna