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

Cloudflare 521 Error: How to Check Server Logs

If you're seeing a Cloudflare 521 error, it means Cloudflare tried to connect to your origin ...

Fix Cloudflare Wildcard Subdomain Not Working

If you've set up a wildcard DNS record in Cloudflare (e.g., *.example.com) but s...

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

Clear Chrome Certificate Cache to Fix NET::ERR_CERT_AUTHORITY_INVALID

When you see NET::ERR_CERT_AUTHORITY_INVALID in Chrome, it usually means the browser...

VSCode Terminal Not Opening on Ubuntu: Fixes That Work

You open the integrated terminal in VSCode on Ubuntu, but nothing happens—no shell, no error, jus...

Fixing Nginx Upstream Connection Refused and Permission Denied

If you see connect() failed (111: Connection refused) or connect() failed (13:...