When I open the website (complete or skeleton) as they are provided in the download and click in the Database Explorer to expand Database diagrams, I get the Message: 'This database does not have a valid dbo user or you do not have permissions to impersonate the dbo user, so database diagramming is not available. Do you want to make yourself the dbo of this database in order to usee database siagramming?'. When I click Yes, I get the message 'This database does not have a valid dbo user or you do not have permissions to impersonate the dbo user, so database diagramming is not available. Ensure the dbo account is valid and you have impersonate permission on the dbo account.' And this only offers me an 'OK' button to click on.
Any suggestions on where and how to deal with dbo account and impersonate permissions in SQL Server Express ? Any help will be greatly appreciated

I got this message too and found a an article on it.
It saids to download express manager.
connect to the database
properties
files
change owner to [sa]
this works but not sure why it didn't work with the pc logon owner

Thanks!

hi there, im getting the same error, could you please explain in details of how to change ownership to sa, i downloaded the microsoft sql management studio express. but i dont know where to change the ownership. cheers

asp.net...<:!:>

Hello,

actually, the problem lies in something different:

• in the "Server Explorer" window, click once on your SQL database file name (for example, "MySQLdatabase.mdf")
• now have a look at the "Properties" window, row "Owner". It should read something like "MyPCName\John User"
• if you are not logged in as "John User", then this is your problem
• if you're logged in as "John User", right click your "My Computer" icon and select "Properties"
• if your "Full computer name" in the "Properties" > tab "Computer Name" window is NOT "MyPCName" (as in the above example), then this is your problem

Michal Kreslik
michal.kreslik(at)kreslik.com

Here is a solution for the problem:

http://geertverhoeven.blogspot.com/2...valid-dbo.html