TLS negotiation failed with a incoming connection on the Proxy side TLS endpoint. Remote Endpoint: %1 Reason: %2 Cause: The ...

TLS negotiation failed with a incoming connection on the Proxy side TLS endpoint.

Remote Endpoint: %1
Reason: %2

Cause: The Proxy peer may not be configured to send connections to the port Mediation Server is listening to, or the certificate of the Proxy peer is not recognized by the Mediation Server.
Resolution:
Check the Mediation Server and Proxy peer certificates are configured correctly.  Check if the MEDIATIONSERVER_MAJOR_CONFIGURATION_ALARM (Event ID: 25057) has been fired.  Check whether the remote endpoint a known peer.