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Fix Port Already Allocated Error in Windows Security - Fix Cloudflare DNS Not Working with VPN Connection-How to Fix Port Already in Use by Windows Defender Firewall

Updated 2026-06-13 15:12:08office-tools
Fix Port Already Allocated Error in Windows Security - Fix Cloudflare DNS Not Working with VPN Connection-How to Fix Port Already in Use by Windows Defender Firewall
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.