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How to Fix Cloudflare Error 525 SSL Handshake Failed - Windows 11 Defender Won't Open: Troubleshooting Guide-Fix Windows Store Error 0x80073cf9 Sync Issue

2026-06-13 12:36:27network-tools
How to Fix Cloudflare Error 525 SSL Handshake Failed - Windows 11 Defender Won't Open: Troubleshooting Guide-Fix Windows Store Error 0x80073cf9 Sync Issue

Final checklist

  • Confirm that the same symptom is gone after a restart or refresh.
  • Keep the smallest working change and undo temporary diagnostic settings.