Fix OneDrive Version Mismatch Error 0x8004de40 - Resolve 'File Locked by System' in Windows Defender-Outlook Connection Error: Internet Not Reachable

Updated 2026-06-14 11:40:39security-tools
Fix OneDrive Version Mismatch Error 0x8004de40 - Resolve 'File Locked by System' in Windows Defender-Outlook Connection Error: Internet Not Reachable
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.