During some lab testing of a Lync Server 2013 Enterprise front-end pool upgrade to Skype for Business 2015 Server, issues with the SQL database were reported by the Front End Servers in the form of an incorrect version of SQL found after going ahead too quickly. Simply put, replication should have been confirmed before going ahead and wasn’t.
Two Services would start and then stop. They were:
Lync Server File Transfer Agent
Lync Server Master Replicator Agent
Despite trying to restart these services, they would stop almost as soon as starting. Over to the event viewer to see what was happening:
Event ID 1021 Source LS File Transfer Agent Service
Microsoft Lync Server 2013, File Transfer Agent successfully registered with the back-end, but a schema or sproc version mismatch was detected. The service will not start until this problem is resolved.
Database version: Actual = 10.15, Expected = 10.13.
Cause: Installation error.