Have you ever seen this error on a Groove 2007 Relay server?--Decrypting Message Registration. IDispatch error #101.  In addition, I can't access gms.dll on the Groove 2007 management server, although it appears to be properly configured.  When users attempt to access it from IE, they cause application event to be written to the management server event log that indicates that the request was neither a post nor a get, even though a network monitor trace shows that a get was attempted.  I'm fairly sure that the Relay errors and the gms.dll problem are related, but that might be especially obvious

 

 

This set of problems turned out to be caused by a couple of things.  I couldn't access gms.dll.  Microsoft says they disabled this diagnostic feature because it was a security vulnerability.  The IDispatch error #101 seems to have been caused by a corrupted Groove Management public registry key on the Relay servers.  I was able to resolve it by re-applying the public Management key to the Relay servers.