Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You're connected to WiFi, the icon shows full bars, but websites won't load. This usually...

When you run npm install or npm start and see npm ERR! package.js...

How to Fix Git Clone Timed Out and Permission Denied Errors
When you run git clone and see errors like timed out or permissio...

Python Virtual Environment Not Activating on Mac: Fixes
You open Terminal, run source venv/bin/activate, and nothing happens—or you get an e...

Fix Nginx Permission Denied Error for www-data User
If you see errors like nginx: [emerg] open() "/var/www/html/index.html" failed (13:...

Fix Nginx 502 Bad Gateway in Docker Alpine
You have an Nginx container running on Alpine Linux, and it returns a 502 Bad Gateway. This usual...