Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

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Latest checklists

If you see "Secure Connection Failed" in Firefox on your Mac, the browser is blocking the...

When you see fatal: unable to access '...': SSL certificate problem: unable to get ...

npm package.json Not Found After npm init
You run npm init, answer the prompts, and then try to install a package or run a scr...

Fix Nginx Redirect Loop After SSL Setup
You've set up SSL on your Nginx server, but now visitors get stuck in a redirect loop—HTTP→HT...

Fixing Nginx Upstream Connection Refused and Permission Denied
If you see connect() failed (111: Connection refused) or connect() failed (13:...

Fix 'node sass build failed permission denied' Error
You're running npm run build and hit Error: EACCES: permission denied