SQL Server 2005: Cannot install database diagram support objects

Question

I have run into a "good old" problem on SQL Server 2005 Express. When I select the "Database Diagrams" node in SSMS, I get the message:

Database diagram support objects cannot be installed because this database does not have a valid owner (...)

I have fixed this before, and a google-search gives loads of hits, so it's a well known thing. However, the suggested remedy is always the same, either:

1) Choose database properties, select the Files page and set the owner to a valid login, or

2) Execute this:

EXEC sp_dbcmptlevel 'yourDB', '90';
go
ALTER AUTHORIZATION ON DATABASE::yourDB TO "yourLogin"
go
use [yourDB]
go
EXECUTE AS USER = N'dbo' REVERT
go

The problem is that the database already seems to have a valid owner:

1) The dbo user is mapped to my login 2) My login is set up as the database owner on the db owner/files page 3) The compatibility level is 90 (SQL Server 2005)

The above SQL has no effect - the "EXEC sp_dbcmptlevel" of course does nothing, the "ALTER AUTHORIZATION" executes, but seems to accomplish nothing, and the REVERT gives the message:

Could not obtain information about Windows NT group/user 'MYDOMAIN\MyLogin', error code 0x54b

That last bit has me puzzled, and may be a clue. The login certainly exists - I am currently logged in with it, and the computer is also in the domain.

Any clues?

Answer 1

Yeah, so I guess I'll have to do all the work myself, huh ;-)

Turns out I was right about the "could not obtain information about login" message being a clue.

The trouble was for SQL Server to validate my login. The server is running on a workstation (laptop), and I was not actually connected to the domain for that login. When I finally realized this, and connected via VPN to the corporate network, everything worked like a charm.