I need to revive an error, that seemed to have been appeared two times with other people (in Oct 2025 and Jan 2026) but in one case magically solved itself, in the other the thread creator never replied further, so the topic was closed.
Here are both topics:
For me the same happens now on Firefox (my actual browser), but NOT on Edge, when I started to do the first workshop of the Python Certification “Build a Report Card Printer”:
fCC console throws:
“// running tests
Error: Timed out waiting for the test worker to initialize”
and I can’t continue with the next Challenge. Bummer. I also deactivated my uBock Origin and NoScript or tried the next challenge with wrong code to no avail.
Here is a hacky picture of the respective browser consoles for further investigation:
Since the challenge works on Edge but not on Firefox, this looks more like a Firefox-specific issue than a problem with your Python code.
I would try clearing the site data for freeCodeCamp first, then reload the challenge and run the tests again. If that does not work, you could also try Firefox Troubleshoot Mode or a fresh Firefox profile to see if an extension, cached data, or a privacy setting is blocking the test worker.
The message:
Timed out waiting for the test worker to initialize
suggests that the test worker is not loading correctly in Firefox. It would also be useful to know if the same thing happens in a private window or only in your normal Firefox profile.
