Unable to start services after patching - msdb110_upgrade.sql' encountered error 574, state 0, severity 16.

Question : During a recent round of patching , I've been frequently seeing msdb110_upgrade.sql' encountered error 574, state 0, severity 16 in the Event Viewer when the service for the SQL Server Instance is attempting to start.

How can I resolve this issue? The service will not currently start.

I've checked in the SQL Server Error log file via a text editor and can see A problem was encountered granting access to MSDB database for login '(null)'. Make sure this login is provisioned with SQLServer and rerun sqlagent_msdb_upgrade.sql 

The lines in the SQL Error Log are:

2018-09-09 13:41:56.88 spid5s      Granting login access'xxxx\ID' to msdb database...
2018-09-09 13:41:56.89 spid5s      A problem was encountered granting access to MSDB database for login '(null)'. Make sure this login is provisioned with SQLServer and rerun sqlagent_msdb_upgrade.sql
2018-09-09 13:41:56.89 spid5s      A problem was encountered granting access to MSDB database for login '(null)'. Make sure this login is provisioned with SQLServer and rerun sqlagent_msdb_upgrade.sql
2018-09-09 13:41:56.89 spid5s      

Answer: I've experienced similar issues and on each occasion it's been a different underlying reason . The way I've approached the problem is :

Step 1: Extract the error lines from the SQL Server Error Log file

Step 2 : Start the SQL Service with the trace flag 902   -  so the start command will be :     NET START MSSQL$MYSERVICE /T902

This will give you enough time to fix the root cause ,

Step 3 : When the fix is is applied then restart the sql service but without the trace flag

 Read More on trace flags

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