Error When Upgrading SCCM Current Branch

This Post only applies to environments where the Primary site and the SQL database are on the same server

When upgrading SCCM to the latest CB you may have noticed when monitoring the log file with CMtrace (cmupdate.log) that you start receiving continuous errors for 30-40 minutes with the following text:

Failed to open registry key SOFTWARE\Microsoft\SMS\COMPONENTS\SMS_EXECUTIVE\Threads\SMS_REPLICATION_CONFIGURATION_MONITOR (0), sleeping for 60 seconds

After around 40 minutes you start to see the log file containing the following text:

WaitForRegistryNotification timed out trying to register registry notification SOFTWARE\Microsoft\SMS\COMPONENTS\SMS_EXECUTIVE\Threads\SMS_REPLICATION_CONFIGURATION_MONITOR

Monitoring job timed out waiting for thread component SMS_REPLICATION_CONFIGURATION_MONITOR to be running.

The reason this happens is because the SMS_REPLICATION_CONFIGURATION_MONITOR component is not required for environments where the primary site and the SQL database are on the same server. The good news is this is not anything to be alarmed about and you can safely ignore the errors and the upgrade will eventually finish. The only downside is you have to wait for the time out which makes the upgrade process longer. Hopefully this will be resolved in future upgrades but it still exists in 1802 and earlier at the moment.