We have developed an assembly for SQL Server 2008 R2.
The assembly has been working for a week. The managed stored proc inside the assembly was working fine for the
This is weird. I had the same issue but I confirmed that the dbo account was valid via running a quick query: SELECT 'TEST' AS Test EXECUTE AS USER = 'dbo' I also verified that Trustworthy was set to True.
What fixed it for my box was changing the "assembly owner" from dbo to my own user and afterwards back to dbo.