Website broke.
Let's find it in 5 minutes.
80% of site breaks come from the same 4 causes. Here's how to match your symptom to the fix — fast.
Start here — takes 30 seconds
Open DevTools (F12) → Network tab → reload the page. Any red 404s? That filename is your answer — it's the exact file that's missing.
No 404s? Go to GitHub → Actions tab. Red X on the last run = live site is still on the previous build.
Match your symptom to the fix
index.html didn't make it into _site/. Add it to your build output.
JavaScript error crashing on load. Check Console (F12) for the red error line — it's usually a missing variable or undefined function.
Deploy failed silently. Check Actions tab. Or hard-refresh in incognito: Ctrl+Shift+R
Roll back first, debug after: git revert HEAD --no-edit && git push
Almost always the build script
Run the build locally and check what's actually in the output folder:
bash build_site.sh ls -la _site/
If the file isn't in _site/ locally, it's not on the server. That's your root cause.