These errors will ultimately come down to a mistake somewhere in your code, probably just one, but it causes all the macro stuff to break down and look a lot worse than it is.
Make sure your class names have the correct prefix, your generated.h header is included, you’re using the appropriate GENERATED_XXX_BODY macro for the type etc.
Oh, and if in doubt, close your project, right click on the UPROJECT file and ‘Generate Visual Studio Files’, then re-open.