In the DarkGDK installation folder, there is a PDF detailing the installation of the API into visual studio. At the bottom are detailed instructions on how to go about linking visual studio to the DirectX SDK, and following them may very well help with your errors. If you've already done so I apologise.
Usually Visual Studio will complaining about missing files (especially relating to various Direct3D files) when the correct file paths are not set within Visual Studio itself, rather than the project.
EDIT:
By the by, I've literally just re-installed the GDK using the
August 2009 DirectX SDK and got the same dxerr9.lib error. Just remembered, I solved this by going into my DirectX installation folder, going to the lib/x86 folder and finding the "DxErr.lib" file. I copied this and renamed it "dxerr9.lib". Stuff now works (just gotta go through the whole multiplayer.lib situation).
Could I possibly get a confirm on anyone else whose used this solution to the problem? It may cause errors down the line, so be careful.
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