I had a similar Problem.
-In ur proect folder delete any interdimate folders ui can find (there can be more then one in plugin for example)
- delete the binaries ur compiling. in my case i delted the compilede.exe + the plugin.dll and the project dll. like in … UnrealEngine\Projects\Tutorials_CplusPlus\Binaries\Win64
This will reload ur project. if it still doesnt work look into ur project.log. might be a c++ class error and then u have to fix it in Visual Studio first