Knowledge base for software setup, errors, and daily tool work.

Cloudflare Wildcard Subdomain Troubleshooting Checklist

When you set up a wildcard DNS record (e.g., *.example.com) in Cloudflare, subdomain...

Chrome Startup Crash with No Error Message: Fixes That Work

Chrome crashes on startup with no error message—just a sudden close or a frozen window. This ofte...

Fix Git SSL Certificate Problem: Unable to Get Local Issuer Certificate

Nginx Upstream Connection Refused: Diagnosis and Fixes

When Nginx returns a 502 Bad Gateway or logs "upstream connection refused", it means Ngin...

Fix 'docker network not found' Error on Mac

If you're on a Mac and Docker returns network not found when you try to run or i...

Fix Cloudflare Wildcard Subdomain DNS Propagation Delay

You set up a wildcard DNS record (e.g., *.example.com) in Cloudflare, but new subdom...