Fix Windows Defender Sync Error 504 Gateway Timeout - Fix ipconfig flushdns Not Working-Windows Defender Threat Service Stopped: How to Fix

Updated 2026-06-14 01:07:16macos-help
Fix Windows Defender Sync Error 504 Gateway Timeout - Fix ipconfig flushdns Not Working-Windows Defender Threat Service Stopped: How to Fix
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.