Workaround to avoid WPF Designer Error in VS 2008 SP1

If you are working with the WPF designer of Visual Studio 2008 SP1 you might get the following error message:


Object reference not set to an instance of an object.
at MS.Internal.Package.VSIsolationProviderService.CreateIsolationProvider(String identity, AssemblyReferenceProvider assemblyReferences, IEnumerable`1 assemblyFolders)
at MS.Internal.Providers.VSDesignerContext.GetIsolationProvider(IServiceProvider provider, IVsHierarchy hierarchy, AssemblyReferenceProvider assemblyReferences)
at MS.Internal.Providers.VSDesignerContext.Initialize(IServiceProvider provider, IVsHierarchy hierarchy, UInt32 itemid, Object docDataObj)


If you get this error, make sure your startup project is a managed .NET project. The WPF designer seems to have a problem with C++ projects selected as startup project of your solution.
You can still start the win32 application for debugging by configuring the debug options of your managed .NET project ("Start external program" setting).