I am developing a simple web application. There's a single module with a single WEB facet. I added another source root to the module. I spent ten minutes debugging because my app still did not work. Only then I found an innocent looking checkbox that I needed to select to actually use the new source root. Please: If there's only a single facet that uses sources (EJB or WEB) then please add the source root to that facet automatically. Ideally, If there more than one facet, you should ask the user to which facet's source roots then new source root should apply. At the very least: Warn if a source root is configured but not actually used in any facets.