I'm running Windows 8.1 (Pro) and the latest C2 Beta (r187) and I see this error too. In Visual Studio 2013 Ultimate (latest), i was presented with this error on launching the .sln file. In VS, the 'Shared' project has an asterisk next to it with the warning 'This project is incompatible with this current edition of Visual Studio'.
When I launch the Desktop or Phone project's emulator, the emulator freezes at the C2 loading icon and in VS it reports that it cannot find the project images. C2 exports the project images to an incorrect depth of the project tree. This bug has been there for quite a few C2 betas.