Upgrade to SQL Server 2017 Fails Windows Server 2016 - Fully Patched
Sql Server 2016 SP2 CU3 -> Upgrade to 2017


In place upgrade fails with error message:


  Wait on the Database Engine recovery handle failed. Check the SQL server error log for potential causes


See this in the event log:


  Script level upgrade for database 'master' failed because upgrade step 'ISServer_upgrade.sql' encountered error 917, state 1, severity 15. This is a serious error condition which might interfere with regular operation and the database will be taken offline. If the error happened during upgrade of the 'master' database, it will prevent the entire SQL Server instance from starting. Examine the previous errorlog entries for errors, take the appropriate corrective actions and re-start the database so that the script upgrade steps run to completion.


I'm able to recover from backup, but I need to get this server upgraded. 

What am I missing here?

Here is what I'll be trying in a bit (from here)

1) Execute Diff backup in SQL Safe
2) Create Snapshot in VCD
3) Perform Upgrade
4) When fails add -T902 flag to startup parameters
5) Start SQL Server
6) Install CU 11
7) Remove -T902
8) Start SQL Server
Here is what resolved the error, copied lovingly from a Microsoft forum 

Here is what I'll be trying in a bit (from here)

1) Execute Diff backup in SQL Safe
2) Create Snapshot in VCD
3) Perform Upgrade
4) When fails add -T902 flag to startup parameters
5) Start SQL Server
6) Install CU 11
7) Remove -T902
8) Start SQL Server


The key here was to start up sql server with the -T902 parameter and then install the latest CU (which is 11 right now)