Microsoft released a second out-of-band update for Windows 11 to address Outlook crashes caused by a bug in its January 2026 security update affecting cloud-stored files.
The update targets a specific issue where applications that open or save files in cloud-backed locations become unresponsive or display error messages. Users encountered Outlook crashing or failing to launch when personal storage table (PST) files were located in cloud services such as OneDrive. This malfunction stemmed directly from the January security update, prompting Microsoft to deploy an emergency patch outside its standard schedule.
This marks the second instance this year that Microsoft has provided a last-minute correction for problems originating from the same January security update. Last week, the company issued a prior out-of-band update to resolve separate disruptions: certain Windows 11 devices were unable to shut down or enter hibernation, while Windows 10 and 11 systems experienced failures in remote login connections.
Microsoft reserves out-of-band updates for critical defects that demand immediate resolution and cannot align with the regular monthly Patch Tuesday cycle. The most recent patch functions as a cumulative release, meaning users need only install this single update to rectify all known issues linked to the January security update.
