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Fix 'Outlook Data File Cannot Be Accessed' Error in Outlook 365 - MsMpEng.exe High CPU Fix Guide-Windows Defender Service Permission Denied Troubleshooting

2026-06-13 16:08:32browser-issues
Fix 'Outlook Data File Cannot Be Accessed' Error in Outlook 365 - MsMpEng.exe High CPU Fix Guide-Windows Defender Service Permission Denied Troubleshooting

Final checklist

  • Confirm that the same symptom is gone after a restart or refresh.
  • Keep the smallest working change and undo temporary diagnostic settings.