RDP: Suddenly plagued with "Because of an error in data encryption..."

Remote Desktop Connection
---------------------------
Because of an error in data encryption, this session will end. Please try connecting to the remote computer again.

To resolve this issue, follow these steps:

1. Start Registry Editor.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\TermService\Parameters
3. Under this registry subkey, delete the following values:
   • Certificate
   • X509 Certificate
   • X509 Certificate ID
4. Quit Registry Editor, and then restart the server.

Does anyone have any suggestions please as I'm at a total loss what is happening here.
Thanks.