Troubleshooting
My code won't run or the checks won't pass
Quick fixes when the editor, Run button, or grading isn't behaving.
Most "it won't work" moments come down to a few common causes.
The Run button does nothing
- Give it a second - the first run in a session spins up the sandbox.
- Try a hard refresh (Ctrl/Cmd + Shift + R).
- Some browser extensions block the code sandbox - try an incognito window.
My code runs but the checks fail
- Read each check label carefully; they tell you exactly what's expected.
- Compare your output to the expected output character-for-character (spaces and capitalisation matter).
- Stuck? Open Ask Puff and use "Why did it fail?" for a hint.
I want to start over
Hit the ↺ Reset button in the editor to restore the starter code. Your draft auto-saves as you type, so you won't lose completed work.
If something's genuinely broken, let us know with the lesson name and what you saw.
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Still need help?
Can't find the answer here? Reach the team directly - we read everything.