This document is intended to help you through frequently encountered weird technical failure scenarios (WTFS) in IntelliJ. It will be populated as questions arise.

I can’t run my Java files

If your files look like this then you might have opened a subdirectory of the assignment. When starting an assignment for the first time, make sure you open the whole assignment. After you make sure you have opened the whole assignment, right-click on the folder for the assignment, e.g. lab02, then Mark as -> Sources Root.

Variables show up as red in IntelliJ

This means that you forgot to add library-su21 as a library for this project! Every time you start a new assignment you must re-add the .jar files. To do this, under the “File” menu, choose “Project Structure” and “Libraries”, and then add the library-su21 inside your repo.

Everything looks right but it still doesn’t work!

Sometimes the easiest thing is to simply do it all over again. Even if you know you just did everything correctly, starting over very often just fixes the problem. First close the project (from the “File” menu, choose “Close Project”) and then reopen the project from the beginning.