Visual Studio 2008 keeps me entertained all day long:) I have a really complicated project, with several tables and views and stored procedures hooked upon it. I'm using XSD as an intermediate abstraction layer. The error message "Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints" kept haunting me for days; I double checked anything:
- there were no duplicate keys whatsoever
- there were no NULL values, I experienced with IsNull(..) for fields
- even empty tables had this error.