C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys

Apparently, containers created with sn.exe are created below this directory.

Failed to generate a strong name key pair -- Access is denied.

The sn.exe error message Failed to generate a strong name key pair -- Access is denied. might be caused by a user with to little access rights on this folder.

The required access rights can be granted as admin with (Rene being the username):

cacls.exe “%ALLUSERSPROFILE%\Application Data\Microsoft\Crypto\RSA\MachineKeys” /E /G Rene:F