Mediation Server was able to contact the A/V Authentication Service. However, there were no valid relay candidates returned ...

Mediation Server was able to contact the A/V Authentication Service. However, there were no valid relay candidates returned to Mediation Server.  Calls may still work, but the Mediation Server will not be able to send calls through the A/V Authentication Service. This event is throttled after 5 consecutive attempts at getting the relay candidates.

Relay Addresses: 
%1
Cause: The Relay Addresses may no longer be able to be DNS resolved from the Mediation Server machine.  The A/V Authentication Service may not be configured correctly.
Resolution:
Verify the Mediation Server machine can resolve the Relay Addresses.  Check if the A/V Authentication Service is configured correctly.