I have included a code library as a dependency in my project (under Project -> Dependencies...) however I'm unable to include the header file from that code project "Unable to find the file on disk". Do I also need to manually add the code library path as an include path? I would assume that adding it as a dependency would take care of that for me?
This is abnormal. Including dependency project should take care of all automatically.
I suspect that the fitter file keeps old path or some reference, which causes this error. Try following: close project and Creator IDE; delete *.cyfit file in the project folder and Generated_files folder.