Well looks like the DirectX version is targeted for .NET 4.5 whereas WIndowsGL is .NET 4. So I suppose DirectX is supposed to target Windows 8? Something of a pain for non-Windows 8 DirectX users then! So I can cure it by building the framework myself and copying the files across however would prefer to keep it via nuget and so if anyone has a solution for NuGet local stream would be appreciated.