Event will SHOW: Sync Failed: USSCommunicationError: WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel
Logs in C:\Program Files\Update Services\LogFiles\SoftwareDistribution.log will SHOW:
The given certificate chain has not Microsoft Root CA signed root (800B0109) The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel
SOLOUTION https://support.microsoft.com/en-ca/help/4535405/wsus-does-not-sync-with-microsoft-on-wsus-3-0-sp2-2008-r2-servers-beca
