For me, ProjectTypeGuids in the .csproj file was missing (the new project worked for me, so I just compared the project files), so if you add this to the .csproj file in the PropertyGroup, then I had all the WPF types available for adding:
<ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
Michael
source share