Lync 2013, Cumulative Update 7 – nach Reboot noch alles klar, nach einem späteren Frontend Servicerestart plötzlich Event ID 12303/LS Server (The protocol stack reported a critical error: code 800B0109 (CERT_E_UNTRUSTEDROOT). The service has to stop.) und 14649/LS Protocol Stack A serious problem related to certificates is preventing Lync Server from functioning. Unable to use …