While updating TFS 2012 with update 1, the following error was thrown towards the end of the process:
[Info @18:14:02.866] Execution results:
[Info @18:14:02.866] Overall result: Success
[Info @18:14:02.866] Nodes completed: 51
[Info @18:14:02.866] Nodes succeeded: 51
[Info @18:14:02.866] Nodes skipped: 23
[Info @18:14:02.866] Nodes with errors: 0
[Info @18:14:02.866] Nodes with warnings: 0
[Info @18:14:02.866] Number of error messages: 0
[Info @18:14:02.866] Number of warning messages: 0
[Info @18:14:02.866] Number of info messages: 2
[Error @18:16:51.645] TF400744: An error occurred while executing the following script: SetRecoveryModelToSimple.sql. Failed batch starts on the line 1. Statement line: 1. Script line: 1. Error: 5069 ALTER DATABASE statement failed.
As implied from the error, the upgrade process failed to execute a script that sets the SQL Recovery Model to simple. The solution was to set the TFS databases (Tfs_Configuration, Tfs_DefaultCollection and Tfs_Warehouse) Recovery Model from Full to Simple prior to applying the update.
The aggravating part is that error forced us to rollback the entire update. After restoring the database to a point before the update has taken place, we uninstalled TFS 2012 App Tier completely and repeated the update process. On the second attempt when the Recovery Model in simple mode, the update applied successfully. Just need to not forget to switch it back to Full Recovery Model when done.