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How to Fix Cloudflare Error 521: Origin Server Unreachable - How to Fix DNS Problems in Windows 11 When Wi-Fi Is Connected-Fix DNS Probe Finished NXDOMAIN After Changing DNS

Updated 2026-07-28 08:48:47developer-tools
How to Fix Cloudflare Error 521: Origin Server Unreachable - How to Fix DNS Problems in Windows 11 When Wi-Fi Is Connected-Fix DNS Probe Finished NXDOMAIN After Changing DNS
Likely symptom
Likely cause
Safe rollback

Verification route

  • Repeat the original action, not only a simplified test case.
  • Restart the app or reload the service after configuration changes.

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