Recently, I saw this error while trying to open up a .dbproj project file on my Visual Studio 2008 Team Suite. I thought that team suite might support all the project types, but that was not the case. I tried to figure out what’s the issue here and figured out that we need to install “Visual Studio Team System 2008 Database Edition GDR” to get the .dbproj project support to Visual Studio.
You can download the VSTS 2008 Database Edition GDR from here.
Please note: The database project is supported only in Team Suite and Database Edition on Visual Studio 2008.