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Fix Windows Security 404 Error Not Loading - Windows Defender Not Starting After Fresh Install? Fix It-Troubleshoot Error 0x80070020 Port Allocation

Updated 2026-06-13 16:07:19cloud-software
Fix Windows Security 404 Error Not Loading - Windows Defender Not Starting After Fresh Install? Fix It-Troubleshoot Error 0x80070020 Port Allocation
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.