Microsoft has confirmed that its latest Windows updates, released on January 13, 2026, are causing several applications to freeze when accessing files stored on cloud services like OneDrive and Dropbox. This is just one in a series of critical bugs discovered in the recent patch.

This is a significant headache for anyone relying on cloud storage for their daily workflow. The most specific and frustrating victim of this new bug is Microsoft Outlook. If you happen to store your Personal Storage Table (or PST) files on OneDrive, Outlook can become completely unresponsive. The only way to get Outlook running again is to kill the app manually or reboot your PC.

Other than the freezing, the bug can also prevent sent emails from showing up in your Sent Items folder. You might also see emails randomly redownloading, which is pretty frustrating.

When you break down Microsoft’s official guidance, it becomes clear the company is struggling to manage its own ecosystem. The official workaround for the Outlook issue is just to move those PST files out of OneDrive entirely. While putting large PST files in OneDrive is often discouraged unless you are strictly using it for backup, changing a functional workflow because of a mandatory security update is a big adjustment.

To me, it looks like Microsoft is having issues with basic integration testing between its flagship operating system and its core productivity suite. This cloud storage bug, tracked under KB5074109, is not confined to just one version of Windows. It affects users across Windows 11 versions, including 25H2, 24H2, and 23H2, as well as Windows 10 versions like 22H2 and older LTSC editions.

This freezing issue is just the newest problem stemming from that same January patch. Just days before Microsoft acknowledged the cloud storage issue, it had to release an emergency out-of-band fix, KB5077744, to fix widespread connection failures. That earlier bug blocked users from logging in to remote connection applications, specifically affecting Azure Virtual Desktop and Windows 365.

We recently reported on how the January update caused some Windows 11 23H2 devices to refuse to shut down or hibernate, forcing another round of troubleshooting by system administrators. If you are struggling with the freezing apps, Microsoft has offered some obvious advice. The company’s official suggestion is to ‘contact the application developer’ to find other ways to open your data.

Since the application developer is often Microsoft itself, that advice feels a bit circular. If Outlook is locked up, the advice is to use webmail if your email provider supports it, which is the definition of avoiding the problem rather than solving it.

Microsoft says it is actively working on releasing a resolution for this issue as soon as possible and will provide an update when more information is available. Given the sheer number of critical issues that have appeared shortly after this patch release, it feels like Microsoft needs to take a serious look at its update quality control before rolling out mandatory security fixes.