Microsoft has released a second emergency out-of-band update for Windows 11, addressing a critical issue that caused Outlook and cloud-backed applications like OneDrive and Dropbox to become inoperable after the January 2026 Patch Tuesday updates. This update, KB5078127, is designed to fix a problem that affected multiple versions and editions of Windows, including Windows 11 version 23H2, Windows Server editions, and more. The issue caused some applications to become unresponsive or encounter unexpected errors when opening or saving files to cloud-based storage. In certain Outlook configurations that store PST files on OneDrive, Outlook may hang and fail to reopen unless the process is terminated or the system is restarted. Users may also see missing sent items or previously downloaded emails being re-downloaded. This is the second emergency out-of-band update Microsoft has pushed out for Windows 11 users in a week, highlighting a challenging start to the year for the company and Windows. The original Patch Tuesday release introduced issues that caused PCs running version 23H2 to fail to shutdown or hibernate, and also broke signing into Windows 11 PCs using Remote Desktop. Microsoft addressed these issues in the out-of-band update issued on January 17, but in the process, broke apps like Outlook, OneDrive, and Dropbox. With the quality bar for Windows at an all-time low, it remains to be seen if the next Patch Tuesday release will bring improvements. The situation is a stark reminder of the importance of thorough testing and quality assurance in software development.
