Even in the current version of IntelliJ Idea an annoying error message might pop up: Load error: undefined path variables. Here's an alternate solution on how to get rid of it if Fix it doesn't fix it.

In my case, a few things had to come together to trigger the mentioned error.

• Programming in PHP.
• Concatenate two variables, for example $start.$end somewhere in your code.
• Using the Evaluate Expression dialog to evaluate this expression during a debug session.

This combination led to the following error message:

The recommended solutions aim to search IDEA's project files (.idea folder, *.iml, workspace.xml, etc.) for the variable name mentioned in the error message. The internal syntax of path variables used by IntelliJ Idea is $<VARNAME>$. Now you can imagine where the problem comes from. So in my case I started to search for $start.$ in the project folder named .idea. Unfortunately nothing was found there.

However, there are other directories used by the IDE to store settings, caches, plugins and logs. Identify the configuration folder (idea.config.path) for your system and search it for $<VARNAME>$. Replace VARNAME with the variable name given in the error message. In my case I searched for $start.$ in folder /home/joerg/.config/JetBrains/IntelliJIdea2021.3.

The search result shows the following figure.

Three positions matching the search query were found in the workspace folder. I formulated the search a little more openly (allowing whitespace before the closing $), but that wasn't really necessary. The third entry relates to the "Evaluate Expression" function. Deleting those 5 lines

saving the file and restarting IDEA brought the solution: The error no longer appeared.