Hi Dave,
Please modify the USER_HEADER_SEARCH_PATHS in the Xcode project (either in the build settings, or by editing the .pbxproj file directly) to:
from something like:
USER_HEADER_SEARCH_PATHS = "../../Support/Inc ../../Support/Modules/**";
to something like:
USER_HEADER_SEARCH_PATHS = "../../Support/Inc ../../Support/Modules/GSRoot ../../Support/Modules/GSRoot/STL/imp ../../Support/Modules/GSUtils ../../Support/Modules/InputOutput ../../Support/Modules/Geometry";
The important parts here are the GSRoot and its subdirectories (add other modules as necessary).
Best Regards,
Tibor