LmCast :: Stay tuned in

Microsoft releases emergency OOB update to fix Outlook freezes

Recorded: Jan. 25, 2026, 4 a.m.

Original Summarized

Microsoft releases emergency OOB update to fix Outlook freezes

News

Featured
Latest

Fortinet confirms critical FortiCloud auth bypass not fully patched

Okta SSO accounts targeted in vishing-based data theft attacks

Hackers exploit critical telnetd auth bypass flaw to get root

Hackers get $1,047,000 for 76 zero-days at Pwn2Own Automotive 2026

Microsoft releases emergency OOB update to fix Outlook freezes

Sandworm hackers linked to failed wiper attack on Poland’s energy systems

Konni hackers target blockchain engineers with AI-built malware

A lifetime of multi-device ad blocking is just $40 in this deal

Tutorials

Latest
Popular

How to access the Dark Web using the Tor Browser

How to enable Kernel-mode Hardware-enforced Stack Protection in Windows 11

How to use the Windows Registry Editor

How to backup and restore the Windows Registry

How to start Windows in Safe Mode

How to remove a Trojan, Virus, Worm, or other Malware

How to show hidden files in Windows 7

How to see hidden files in Windows

Webinars
Downloads

Latest
Most Downloaded

Qualys BrowserCheck

STOPDecrypter

AuroraDecrypter

FilesLockerDecrypter

AdwCleaner

ComboFix

RKill

Junkware Removal Tool

Deals

Categories

eLearning

IT Certification Courses

Gear + Gadgets

Security

VPNs

Popular

Best VPNs

How to change IP address

Access the dark web safely

Best VPN for YouTube

Forums
More

Virus Removal Guides
Startup Database
Uninstall Database
Glossary
Send us a Tip!
Welcome Guide

HomeNewsMicrosoftMicrosoft releases emergency OOB update to fix Outlook freezes

Microsoft releases emergency OOB update to fix Outlook freezes

By Lawrence Abrams

January 24, 2026
08:59 PM
0

Microsoft has released emergency, out-of-band updates on Saturday for Windows 10, Windows 11, and Windows Server to fix an issue that prevented Microsoft Outlook classic from opening when using PSTs stored in cloud storage.
Since Microsoft released the January 2026 Patch Tuesday updates, Outlook app users have been encountering freezes when opening the application if a PST file is stored in cloud storage, such as OneDrive and Dropbox.
A Microsoft Outlook PST file is a data file used by the application to store a user's email and other data locally on their computer instead of on the mail server. In enterprise environments, these files are commonly used to access mail when offline and back up important messages.

"After installing Windows updates released on or after January 13, 2026 (the Originating KBs listed above), some applications might become unresponsive or experience unexpected errors when opening files from or saving files to cloud-backed storage, such as OneDrive or Dropbox," explains Microsoft.
"For example, in some configurations of Outlook that store PST files on OneDrive, Outlook might become unresponsive and fail to reopen unless its process is terminated in Task Manager, or the system is restarted."
"In addition, sent emails might not appear in the Sent Items folder, and previously downloaded emails might be downloaded again. The affected Outlook configurations primarily involve classic Outlook, which is commonly tied to enterprise licensing and is not included with most home installations of Windows. To check your Outlook configuration, see Feature comparison between new Outlook and classic Outlook."
Microsoft releases OOB updates
To address this Outlook problem, Microsoft released the following out-of-band updates today:
Windows 11 25H2 and 24H2: KB5078127 [Download Link]
Windows 11 23H2: KB5078132 [Download Link]
Windows 10 23H2 and 22H2: KB5078129 [Download Link]
Windows Server 2022: KB5078136 [Download Link]
Windows Server 2025: KB5078135 [Download Link] 
Windows Server 2019: KB5078131 [Download Link]
For those affected by this issue, you can install the updates via Windows Update or the Microsoft Download Catalog using the links above.
Last Saturday, Microsoft also released OOB updates for bugs that prevented access to Microsoft 365 Cloud PC sessions and prevented some PCs with Secure Launch enabled from shutting down or entering hibernation.
While previous OOB updates could only be installed manually via the Microsoft Download Catalog, Microsoft says those fixes are now also included in today's updates.
If these issues do not affect your devices, there is no need to install the out-of-band updates.
Instead, admins and users can wait for the upcoming preview update or next month's Patch Tuesday, when the fixes will be rolled out as part of the regular update schedule.

7 Security Best Practices for MCP
As MCP (Model Context Protocol) becomes the standard for connecting LLMs to tools and data, security teams are moving fast to keep these new services safe.
This free cheat sheet outlines 7 best practices you can start using today.
Download Now

Related Articles:
Microsoft shares workaround for Outlook freezes after Windows updateNew Windows RasMan zero-day flaw gets free, unofficial patchesMicrosoft asks admins to reach out for Windows IIS failures fixMicrosoft: December security updates cause Message Queuing failuresMicrosoft: Outlook for iOS crashes, freezes due to coding error

Emergency Update
Microsoft
OOB
Outlook
PST
Windows 10
Windows 11
Windows Server

Lawrence Abrams
Lawrence Abrams is the owner and Editor in Chief of BleepingComputer.com. Lawrence's area of expertise includes Windows, malware removal, and computer forensics. Lawrence Abrams is a co-author of the Winternals Defragmentation, Recovery, and Administration Field Guide and the technical editor for Rootkits for Dummies.

Previous Article

Post a Comment Community Rules

You need to login in order to post a comment

Not a member yet? Register Now

You may also like:

Popular Stories

Fortinet admins report patched FortiGate firewalls getting hacked

Hackers breach Fortinet FortiGate devices, steal firewall configs

Zendesk ticket systems hijacked in massive global spam wave

Sponsor Posts

Discover how phishing kits are sold and deployed. Download the full research report.

Identity Governance & Threat Detection in one: Get a guided tour of our platform

Overdue a password health-check? Audit your Active Directory for free

Exposure Management Index: Insights From 3,000+ Teams. Get The Report.

  Upcoming Webinar

Follow us:

Main Sections

News
Webinars
VPN Buyer Guides
SysAdmin Software Guides
Downloads
Virus Removal Guides
Tutorials
Startup Database
Uninstall Database
Glossary

Community

Forums
Forum Rules
Chat

Useful Resources

Welcome Guide
Sitemap

Company

About BleepingComputer
Contact Us
Send us a Tip!
Advertising
Write for BleepingComputer
Social & Feeds
Changelog

Terms of Use - Privacy Policy - Ethics Statement - Affiliate Disclosure

Copyright @ 2003 - 2026 Bleeping Computer® LLC - All Rights Reserved

Login

Username

Password

Remember Me

Sign in anonymously

Sign in with Twitter

Not a member yet? Register Now


Reporter

Help us understand the problem. What is going on with this comment?

Spam

Abusive or Harmful

Inappropriate content

Strong language

Other

Read our posting guidelinese to learn what content is prohibited.

Submitting...
SUBMIT

Microsoft released an out-of-band (OOB) update to address stability issues experienced by users of the classic Outlook application, specifically when utilizing PST files stored in cloud storage services such as OneDrive and Dropbox. The updates, designated as KB5078127, KB5078132, KB5078129, KB5078136, KB5078135, and KB5078131, targeted Windows 10, Windows 11, and Windows Server, resolving a freeze issue that arose following the January 2026 Patch Tuesday updates. The core problem stemmed from inconsistencies between the application’s behavior when accessing or saving files from cloud-backed storage, leading to unresponsive applications and, in some instances, a failure to properly save sent emails or re-download previously downloaded emails.

This issue predominantly affected classic Outlook, a licensing model commonly associated with enterprise environments and distinguished from the newer Outlook application. The updates aimed to mitigate these disruptions by enhancing the application's interaction with cloud storage, promoting stability and preventing the observed freezes. Simultaneously, the OOB updates concurrently addressed previous stability issues related to Microsoft 365 Cloud PC sessions and prevented Windows PCs with Secure Launch enabled from failing to shut down or entering hibernation. Users experiencing the reported freezes were instructed to install these updates via Windows Update or the Microsoft Download Catalog.

Microsoft’s decision to release these immediate fixes underscores the importance of rapid responsiveness to user-reported issues, particularly those impacting critical productivity applications like Outlook. The OOB update strategy reflects a commitment to provide timely resolutions, regardless of the scheduled Patch Tuesday release cycle. The release highlights the continued need for organizations to diligently monitor updates and proactively address any disruptions to their IT infrastructure.

The situation emphasizes the evolving landscape of email application stability, as users increasingly rely on cloud-based solutions for data storage and access. The resolution paves the way for greater confidence in using classic Outlook within enterprise settings. The inclusion of previously addressed issues related to Microsoft 365 Cloud PC sessions and Secure Launch further strengthens the overall stability of the Windows ecosystem.

The response also demonstrates Microsoft’s commitment to a collaborative approach to software maintenance, proactively soliciting and addressing user feedback via channels such as community forums and news outlets like Bleeping Computer. These updates serve as a valuable case study in the importance of continuous monitoring, rapid response, and effective communication within the software development lifecycle.