Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you're seeing fatal: unable to access 'https://...' : Failed to connect ...:...

Docker Compose Env Variable Not Available in Container: Fix
You define an environment variable in your docker-compose.yml file, but when you run...

Fix Nginx 'upstream connection refused' When Talking to PHP-FPM
You're seeing upstream connection refused in your Nginx error log, and your site...

Fix Docker Nginx 502 Bad Gateway Upstream Error
When running Nginx as a reverse proxy in Docker, a 502 Bad Gateway error with 'upstream' ...

Fix Chrome ERR_CONNECTION_RESET After Router Reboot
If you see ERR_CONNECTION_RESET in Chrome after rebooting your router, you'r...

Fix Firefox Secure Connection Failed Due to Proxy Settings
If you see "Secure Connection Failed" in Firefox and suspect a proxy is involved, you'...