必应池
Home / office-tools / How to Fix Firefox Secure Connection Failed Certificate Error - Troubleshooting Cloudflare 521 Error Post-Restart-How to Reset Windows Security App Settings

How to Fix Firefox Secure Connection Failed Certificate Error - Troubleshooting Cloudflare 521 Error Post-Restart-How to Reset Windows Security App Settings

Updated 2026-07-28 09:08:43office-tools
How to Fix Firefox Secure Connection Failed Certificate Error - Troubleshooting Cloudflare 521 Error Post-Restart-How to Reset Windows Security App Settings
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.