Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

When you run pnpm install and it fails with ETIMEDOUT, it usually means...

When you try to run yarn in the VS Code integrated terminal and see a Permissi...

How to Fix Git Index Lock File Exists Error
If you see an error like fatal: Unable to create 'path/to/repo/.git/index.lock': Fi...

Fix Nginx Redirect Loop in WordPress
You visit your WordPress site and get a "redirect loop" or "too many redirects" e...

Nginx Upstream Connection Refused: Diagnosis and Fixes
When Nginx returns a 502 Bad Gateway or logs "upstream connection refused", it means Ngin...

Cloudflare 522 Error: Server Response Time Troubleshooting
You're browsing a site and get a Cloudflare 522 error—'Connection timed out' or '...