Microsoft’s January 2026 Patch Tuesday updates for Windows 11 continue to cause disruption, prompting the company to release a second emergency out-of-band update in less than two weeks. The latest fix aims to resolve a critical issue that left Outlook and several cloud-dependent applications unusable on affected systems.
The new update, identified as KB5078127 for Windows 11 versions 24H2 and 25H2, was released on January 24, 2026. It addresses a bug introduced after the January 13 Patch Tuesday rollout, which caused applications to freeze, crash, or return errors when opening or saving files to cloud storage services such as OneDrive and Dropbox.
In official documentation, Microsoft confirmed the scope of the fix, noting that the cumulative update also includes all security protections from the original January Patch Tuesday release, as well as the earlier emergency update issued on January 17.
Outlook and Cloud Apps Hit Hard
The issue proved particularly disruptive for Outlook users whose data files were stored in OneDrive. In some configurations, Outlook would hang indefinitely and refuse to reopen unless users manually terminated the process or restarted their PCs. Reports also surfaced of sent emails disappearing from folders or previously downloaded messages being pulled down again unexpectedly.
While Microsoft initially advised users to temporarily uninstall the January security updates, KB5078127 is intended to eliminate the need for such a workaround.
According to Microsoft’s changelog, the update fixes a problem where applications became unresponsive or encountered unexpected errors when interacting with cloud-based storage following the January 13 update.
Problems Spanning Multiple Windows Versions
Although the worst reports came from Windows 11 24H2 and 25H2 users, Microsoft confirmed that the same fix is being rolled out to other versions, including Windows 11 23H2 and several Windows Server editions. The company is directing users to the Windows release health dashboard for version-specific details.
This marks the second emergency out-of-band update tied to January’s Patch Tuesday. The first, released on January 17, addressed two serious bugs that prevented some systems from shutting down or entering hibernation and blocked Remote Desktop sign-ins. However, that fix inadvertently triggered the cloud application failures now being resolved.
