Microsoft issues rare emergency update to fix Outlook crashes after January patch

Microsoft has released a rare emergency software update to fix widespread problems affecting Outlook users after a January security patch caused email crashes, freezes and other disruptions for millions of Windows customers.

The out-of-band update — released outside Microsoft’s regular monthly patch schedule — addresses issues that left some users unable to reliably access email through Outlook, particularly those using the classic desktop version with locally stored data files synced through cloud services such as OneDrive or Dropbox.

The problems began after Microsoft rolled out its January 2026 security updates for Windows. Shortly after installation, users reported that Outlook would crash on launch, freeze during normal use or fail to properly display sent and received messages.

Microsoft acknowledged the issue and released the emergency fix, saying the update resolves underlying cloud file input/output errors that interfered with Outlook and other applications relying on cloud-based storage.

The company described the release as necessary due to the severity and scale of the disruption. Emergency, or out-of-band, updates are uncommon and typically reserved for critical security vulnerabilities or major system failures.

In addition to Outlook problems, the faulty January update also triggered other Windows issues, including Remote Desktop login failures and problems with system shutdown and hibernation on some devices.

Microsoft urged users to install the emergency update as soon as it becomes available through Windows Update and to restart their devices to ensure the fixes take effect.

The incident adds to growing concerns about update reliability, as Microsoft has issued multiple emergency patches in recent months to correct problems introduced by routine Windows updates.

Affected users who continue to experience issues are advised to check for additional updates or use Outlook’s web version as a temporary alternative while fixes fully roll out across supported systems