Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you've seen the message You are in 'detached HEAD' state in Git, you ...

After a Cloudflare update or configuration change, you might see SSL errors like ERR_SSL_PR...

Fix Nginx Upstream Connection Refused Timeout Error
When Nginx returns 502 Bad Gateway or logs upstream connection refused timeout...

Fix Nginx Configuration Test Failure After Adding Proxy Pass
You add a proxy_pass directive to an Nginx server block, run nginx -t, ...

Fixing Unresolved Paths After Git Merge Conflict Rebase
When you run git rebase and hit a merge conflict, Git pauses the rebase and asks you...

Fix NET::ERR_CERT_AUTHORITY_INVALID in Chrome
When Chrome shows 'NET::ERR_CERT_AUTHORITY_INVALID', it means the browser cannot verify t...