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How to Fix Nginx Upstream Connection Refused on Port 80 - Troubleshooting Cloudflare 521 Error After DNS Change-Fix 'Git Remote Origin Already Exists' Error

2026-07-28 06:24:01macos-help
How to Fix Nginx Upstream Connection Refused on Port 80 - Troubleshooting Cloudflare 521 Error After DNS Change-Fix 'Git Remote Origin Already Exists' Error

Final checklist

  • Confirm that the same symptom is gone after a restart or refresh.
  • Keep the smallest working change and undo temporary diagnostic settings.