Sql Server 2005 Diagram Support

For some reason, when I try to access a database diagram on our new 2005 SQL Server, I get the following error msg:

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

It then goes on to instruct me to either use Properties > Files or ALTER AUTHORIZATION to change the database owner.

Well, I've done that - and it clearly shows that there is an owner of the database, but even if I log in as that owner, the error msg continues to come up everytime I try to access Diagrams.


I found a post to run the following stored procedure which will set the sql server compatability level:

EXEC sp_dbcmptlevel database_name, 90

After running that in the query window of Management Stduio, I get the following msg below on the Messages tab:

"DBCC execution completed. If DBCC printed error messages, contact your system administrator."

I then try to create a new diagram again, and I get the same initial error (at the top of this post).

What do I need to do in order to create a DB diagram?