Fix Windows Defender 502 Bad Gateway Sync Error - Resolve 502 Bad Gateway for RDP via Nginx-Windows Defender Service Error Troubleshooting

Updated 2026-06-14 15:13:58security-tools
Fix Windows Defender 502 Bad Gateway Sync Error - Resolve 502 Bad Gateway for RDP via Nginx-Windows Defender Service Error Troubleshooting
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.