How to Flush DNS on Windows 11 to Fix Internet Issues - Fix 'Secure Connection Failed' in Firefox Mobile-Edge Sync Error 0x80070424 Troubleshooting Guide

Updated 2026-07-28 14:20:23security-tools
How to Flush DNS on Windows 11 to Fix Internet Issues - Fix 'Secure Connection Failed' in Firefox Mobile-Edge Sync Error 0x80070424 Troubleshooting Guide
Before changing system settings, save your work and note the exact error text so you can compare results after each step.

Extra verification checklist

  • Restart the affected app after changing permissions or configuration files.
  • Test the same workflow in a clean browser profile or a temporary user account.
  • Compare the result on another network if the error may be connection related.