zhizhu
Home / developer-tools / Fix Windows Defender Not Opening Error 404 - Cloudflare 525 Error Fix: SSL Handshake Timeout-How to Fix Windows Security Invalid Configuration Error

Fix Windows Defender Not Opening Error 404 - Cloudflare 525 Error Fix: SSL Handshake Timeout-How to Fix Windows Security Invalid Configuration Error

Updated 2026-06-14 03:50:56developer-tools
Fix Windows Defender Not Opening Error 404 - Cloudflare 525 Error Fix: SSL Handshake Timeout-How to Fix Windows Security Invalid Configuration Error
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.