The game module 'xxx' could not be found - open osx-created project on windows

I need to be able to work on a project on both my Mac and my Windows boxes.

I initially created the project on OSX based on the first-person blueprints project, and added some C++ files which I successfully built in XCode. I could switch nicely between xcode and the unrealeditor. Everything was commited to my private git repo.

However, when I check out the project to my windows machine and try to open it in the unreal editor I get “The game module ‘xxx’ could not be found”, I assume because the various base Visual Studio files and build products are missing. I thought I could just open the project in Visual Studio and build once to generate everything but I cant seem to generate the Visual Studio .sln files and whatnot.

I’ve tried right-clicking on the file “myproject.uproject” and selecting “Generate Visual Studio Files” but it does not work. I get no error message or anything there are just no files generated.

What am I missing?