Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

When browsing in Chrome, you may encounter a certificate error stating “invalid authority...

Python Requests Timeout Not Waiting: Fixes and Checks
You set a timeout in Python's requests library, but the call either hangs foreve...

VS Code Git Not Detecting Changes: Step-by-Step Fix
You've edited files in VS Code, but the Source Control panel shows no changes. The git icon m...

Python Virtual Environment Not Activating: Common Fixes
You run source venv/bin/activate (or venv\Scripts\activate on Windows) ...

Fix 'nginx cannot read file permission denied' Error
When Nginx returns a 403 Forbidden or logs "permission denied" for a static file, it'...

Fixing NGINX Upstream Connection Refused SSL Errors
When NGINX logs upstream connection refused for an SSL backend, it usually means the...