We’ve identified an issue while upgrading from previous versions of TFS to TFS 2015 RTM.
Say you are upgrading to TFS 2015 RTM from TFS 2013.4 and you have another TfsWarehouse database that's older , in the same SQL instance used for upgrade, you will encounter the following problem,
Exception Message: VS402623: The Database TfsWarehouse is not configured properly and cannot be automatically repaired. Please contact customer support for assistance. (type ApplicationException)
Exception Stack Trace: at Microsoft.TeamFoundation.Framework.Server.DatabaseConnectionValidator.ComputeIsWarehouseDatabase(ISqlConnectionInfo dbConnectionInfo)
at Microsoft.TeamFoundation.Framework.Server.DatabaseConnectionValidator.ScanSqlInstance(ISqlConnectionInfo masterConnectionInfo)
at Microsoft.TeamFoundation.Framework.Server.DatabaseConnectionValidator.ScanSqlInstancesForDatabases(ISqlConnectionInfo configConnectionInfo, List`1 sqlInstances)
at Microsoft.TeamFoundation.Admin.VerifyCollections.GetCollections(String key)
Info @01:20:06.415] Getting Unreachable Collections
[Info @01:20:06.413] Node returned: Error
[Error @01:20:06.419] TF400314: An error occurred while attempting to verify the collection databases. Verify that the Configuration database is valid.
[Info @01:20:06.419] Completed VerifyCollectionsReachable: Error
This issue is due to the InstanceID of the Old version TfsWarehouse database that is present in the extended properties.
The advice here is to remove the unwanted TfsWarehouse database from the SQL instance on which upgrade is happening (Be cautions not to remove any of your production TFS_Collection/TFS_Warehouse databases).
Content Created by: Vimal Thiagaraj