IntelliJ does not show project folders

Solution 1:

So after asking another question, someone helped me figure out that under File > Project Structure > Modules, there's supposed to be stuff there. If it's empty (says "Nothing to show"), do the following:

1. In File > Project Structure > Modules, click the "+" button,
2. Press Enter (because weirdly it won't let me click on "New Module")
3. In the window that pops up, click on the "..." next button which takes you to the Content root. Find your root folder and select it
4. Click the "ok" button
5. Ignore any warning that says the name is already in use

Solution 2:

I had to quit Intellij and remove the .idea folder (I stashed it first, just in case). I then re-opened the project and that worked for me. Don't forget to save your configuration (e.g. debug / run configurations) before that, because they will also be deleted.