Failed to connect to Registrar. Stopping service. Check TLS certificate Issuer %1 SerialNumber %2, Registrar FQDN %3 Port ...

Failed to connect to Registrar. Stopping service. Check TLS certificate Issuer %1 SerialNumber %2, Registrar FQDN %3 Port %4.
Resolution:
Verify that the TLS certificate is configured correctly, that the Registrar is running, and that there are no network issues between the servers.