Fix OneDrive Sync Not Connecting After Update - Windows Defender 504 Gateway Timeout Proxy Fix-BitLocker Access Denied: Troubleshooting System Volume

Updated 2026-06-14 13:40:02backup-recovery
Fix OneDrive Sync Not Connecting After Update - Windows Defender 504 Gateway Timeout Proxy Fix-BitLocker Access Denied: Troubleshooting System Volume
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.