Windows 2026 Update Bugs: Fix Outlook Freezes & App Errors

The start of the year has introduced a fresh wave of technical headaches for Windows users, primarily stemming from Microsoft’s own January security update. While intended to patch critical vulnerabilities, this update has inadvertently triggered several disruptive bugs affecting everything from remote access to core applications like Outlook. Some of these issues have been addressed, but others continue to cause significant problems for users across multiple Windows versions.

The primary source of these new complications is the Patch Tuesday update released on January 13th. Its main goal was to address over a hundred security flaws, including several rated as critical. However, the update itself became a catalyst for new glitches. While Microsoft has resolved a couple, several persistent problems remain active and unresolved.

One initial bug disrupted remote access. Users attempting to connect to a Cloud PC via Microsoft Remote Desktop encountered authentication failures, preventing sign-in. This affected Windows 11 25H2, Windows 10 22H2, and Windows Server 2025. Microsoft issued an out-of-band patch on January 17th to correct this, which is delivered via Windows Update for qualifying, affected systems.

A separate issue involved systems with Secure Launch enabled, a security feature for managed organizational PCs that guards against bootkit malware. After the January update, these systems would restart instead of shutting down or hibernating properly. This bug, limited to Windows 11 23H2, was also fixed by the January 17th patch, available through Windows Update for impacted devices.

A more widespread and currently unfixed problem cripples the classic desktop version of Microsoft Outlook. Triggered by the same January update, the application freezes with a “Not Responding” message upon launch. Even if users manage to get it running, emails fail to appear in the Sent Items folder, and the program repeatedly redownloads the same messages. This bug appears linked to having Outlook PST data files stored on OneDrive. It impacts a broad range of Windows versions, from Windows 10 22H2 to the latest Windows 11 25H2 and several Server editions.

Microsoft has not yet released a permanent solution but suggests temporary workarounds. These include using Outlook on the web, moving PST files out of OneDrive to a local location, or uninstalling the problematic Windows Update entirely using the company’s support guides.

Closely related is another bug causing applications to freeze or error when opening or saving files to cloud storage services like OneDrive or Dropbox. Affecting the same Windows versions as the Outlook issue, Microsoft has acknowledged this problem and stated a fix is in development.

An additional, inconsistent bug prevents certain applications from opening, displaying error code 0x803f8001. This has been reported with apps like Notepad, the Snipping Tool, and manufacturer utilities like ASUS Armoury Crate. The error is often tied to Microsoft Store license validation problems, potentially due to a corrupted cache or sync issue. Interestingly, some reports indicate the January 13th update actually resolved this problem on some Windows 11 systems, highlighting the inconsistent nature of these bugs.

This pattern of update-induced problems is unfortunately familiar. Windows 11, particularly after the 24H2 release, faced a challenging first half of 2025 riddled with bugs, many created by Microsoft’s own patches. The subsequent 25H2 update in October 2025 stabilized the environment, a critical development coinciding with the end of support for Windows 10. This placed greater responsibility on Microsoft to ensure the sole supported client OS, Windows 11, remained stable. The recurrence of significant bugs introduced by routine security updates undermines that goal, demonstrating that the path to a reliable operating system remains fraught with unexpected setbacks.

(Source: ZDNET)