Here is the code, although the names have been changed to protect the innocent:

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

SET ANSI_PADDING ON

GO

USE master

go

PRINT 'Adding filegroup, DatabaseArchivePartition, for archive partition data.'

ALTER DATABASE MyDatabase

...

Already did this, as I said I triple checked and there are NO duplicate IDs and there are no nulls.