If you look in project settings (ctrl-shift-alt-s), you should see a module structure. If you instead see “Nothing to see”, do the following:
- In Project Structure -> Modules, press the + button,
- press enter (since, for some weird reason, it won’t let me click on “New Module”)
- In the window that pops up, click on the “…” next to Content root, find your root folder, and select it
- Press ok
- ignore any warning that says the name is already in use (or to that effect)