Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see a 521 Web Server Is Down error when visiting your site through Cloudf...

You're trying to run a Python script on Windows, but you get an error like 'python&...

Fixing Nginx Upstream Connection Refused on Port 443
You see "upstream connection refused" in your Nginx error log when proxying requests to p...

Fix Windows 11 Bluetooth Driver Not Working
You're trying to connect a Bluetooth device in Windows 11, but the toggle is grayed out, devi...

Python Virtual Environment Not Activating in Git Bash: Fixes
You're in Git Bash on Windows, you run source venv/Scripts/activate, and nothing...

Docker Container Exits Immediately on Mac: Fixes
You start a Docker container on your Mac, and it stops within seconds. The container exits immedi...