Microsoft Issues Second Emergency Patch After Windows 11 Update Failure

Another out-of-band release aims to restore Outlook and cloud apps after January’s troubled security updates.

Microsoft has issued a second emergency update for Windows 11 in just one week, following widespread disruption caused by its January 2026 Patch Tuesday release. The latest fix, known as KB5078127, is being rolled out globally to address a critical bug that left popular applications such as Outlook, OneDrive, and Dropbox unusable for many users.

The problems began after the January 13 security updates, which were intended to improve system protection but instead triggered a series of unexpected failures. Users reported that Outlook would freeze or fail to reopen, especially when email data files were stored in cloud folders. Others found that cloud-backed appscould no longer open or save files properly. In some cases, emails disappeared or were repeatedly re-downloaded.

Microsoft initially responded with an emergency out-of-band update on January 17, fixing issues related to Remote Desktop access and system hibernation. However, that update introduced new problems, creating further frustration among users.

The newly released KB5078127 update is designed to resolve these cloud and Outlook-related issues while also including all previous security fixes from January. According to Microsoft, this means users no longer need to uninstall recent updates as a workaround.

The fix applies not only to Windows 11 versions 24H2 and 25H2, but is also being extended to other Windows 11 editions and Windows Server versions. This series of rapid emergency patches has raised concerns about the reliability of recent Windows updates. For many users, January has been a rough start, marked by broken features and repeated fixes. Microsoft will now be under pressure to restore confidence when it delivers its next scheduled Patch Tuesday update.