AS3 libraries' classes not recognized

This keeps happening for me. I have multiple modules which may or may not have dependencies on project libraries, which I have set up using source files. However, when starting up IDEA, it won't recognize some of the libraries' classes (I think usually the last library in the series of dependencies, maybe?).

Opening up the module settings and changing the linkage causes IDEA to recognize it after that. But that's hardly a real solution. 

Thank you!