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Microsoft Outlook cloud-backed PST freeze and reopen failure

Service Disruption
First reported
Last updated
Happening score
H score 13
1 unique sources, 1 articles

Summary

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Microsoft released out-of-band updates to fix Outlook freezes on Windows 10, Windows 11, and Windows Server after the January 13, 2026 updates triggered an availability problem with PST files stored in OneDrive or Dropbox. In affected configurations, Outlook could become unresponsive or fail to reopen, and some users also saw Sent Items anomalies and repeated downloads of previously received mail. The fixes are available through Windows Update and the Microsoft Download Catalog.

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Open Happening

Timeline

  1. 25.01.2026 03:59 2 articles · 4mo ago

    Microsoft releases emergency Outlook fix for cloud-backed PST freezes

    Mitigation Patch Update

    Microsoft released emergency out-of-band updates for Windows 10, Windows 11, and Windows Server to restore classic Outlook availability after January 2026 Patch Tuesday updates caused freezes and reopen failures when PST files were stored in cloud-backed storage such as OneDrive or Dropbox; the fixes are available through Windows Update and the Microsoft Download Catalog.

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