Microsoft fixes Teams, Outlook launch failures on ARM Windows PCs

Recorded: Sept. 11, 2026, 10:02 a.m.

Original

News

Featured
Latest

AdaptHealth confirms 4.1 million people exposed in July cyberattack

Microsoft September 2026 Patch Tuesday fixes 966 flaws, 2 zero-days

Over 36,000 exposed Plex servers vulnerable to recent flaws

New Microsoft Defender 'ShieldCrash' zero-day grants SYSTEM access

Microsoft fixes Teams, Outlook launch failures on ARM Windows PCs

Trezor: 347,000 users targeted in phishing attacks after Brevo breach

Conti ransomware gang member sentenced to 4 years in prison

New Android malware encrypts files, steals data, and harasses victims

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 fixes Teams, Outlook launch failures on ARM Windows PCs

Microsoft fixes Teams, Outlook launch failures on ARM Windows PCs

By Sergiu Gatlan

September 11, 2026
05:39 AM
0

Microsoft has fixed a bug that prevented Teams and Outlook from launching after installing updates released since the August 2026 Patch Tuesday.
The company confirmed last week that this known issue affects users who haven't installed Microsoft Store updates on ARM-based Windows devices (such as the Surface Pro 11 and Surface Laptop 7) running Windows 11 24H2 or later.
"After installing Windows security updates released on or after August 11, 2026, (KB5121003), Microsoft Teams and the new Outlook for Windows might fail to launch or might close unexpectedly on ARM-based devices, such as Surface Pro 11 and Surface Laptop 7," Microsoft explained in a Windows release health update.
"Classic Outlook, Word, Excel, and other applications are not known to be affected. This issue is most likely to occur on new or freshly imaged PCs that have not yet installed any Microsoft Store updates."
Although Microsoft has yet to disclose the root cause, it advised affected customers to update the Auto Super Resolution Package, which enables Copilot+ PCs to use AI to make gameplay smoother, as a temporary workaround.
Fixed by Patch Tuesday cumulative updates
On Tuesday evening, after releasing the September 2026 Patch Tuesday cumulative updates, Microsoft said it has now fixed the bug in KB5124012 and asked users to update their devices.
"This issue was resolved by Windows updates released September 8, 2026 (KB5124012), and updates released after that date," it said. "We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one."
This is the latest in a series of other known issues caused by Windows updates released in August. On August 24, Microsoft also confirmed that August 2026 .NET Framework updates are breaking printing and PDF exporting in apps that use the Windows Presentation Foundation (WPF) UI framework.
Days later, it began rolling out a fix for a bug caused by peripherals with built-in RGB lighting that triggered gaming issues and system crashes with EXCEPTION_ACCESS_VIOLATION" errors on Windows 11 systems.
Microsoft also asked customers to ignore alerts that Microsoft Defender Antivirus has been turned off after installing updates released last month.
This week, Microsoft also resolved known issues that wiped custom mouse settings and Windows desktop settings on some Windows 11 systems after installing the KB5120998 August 2026 preview update.

Build your security blueprint for AI-powered attacks

Join Mikko Hyppönen and security leaders from the NFL, CHANEL, and Atlassian for a two-hour digital summit on what AI-speed attacks change, what defenders should stop doing, and how to validate, decide, fix, and re-validate at machine speed.
Save your seat

Related Articles:
Microsoft Teams, Outlook fail to launch on ARM-based Windows PCsMicrosoft shares temporary fix for Windows 11 gaming issuesMicrosoft blames Windows gaming issues on RGB lighting devicesMicrosoft says August Windows updates may cause gaming issuesMicrosoft fixes bug that wiped Windows desktop settings

ARM
KB5121003
KB5124012
Known Issue
Microsoft
Microsoft Surface
Microsoft Teams
New Outlook
Outlook
Surface Laptop
Surface Pro
Windows
Windows 11

Sergiu Gatlan
Sergiu is a news reporter who has covered the latest cybersecurity and technology developments for over a decade. Email or Twitter DMs for tips.

Popular Stories

Microsoft September 2026 Patch Tuesday fixes 966 flaws, 2 zero-days

September Windows Server updates break Remote Desktop Services

New Microsoft Defender 'ShieldCrash' zero-day grants SYSTEM access

Sponsor Posts

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

EtherHiding Malware on macOS: How Attackers Hide C2 on the Blockchain

Find your gaps before an auditor does. Check your EU CRA readiness in 5 questions.

See how attackers exploit passkey enrollment, and why hardware-bound biometrics raise enterprise identity assurance.

Upcoming Webinar

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

Username

Password

Remember Me

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 resolved a bug that caused launch failures for the Teams and the new Outlook applications on ARM-based Windows PCs following the release of updates from the September 2026 Patch Tuesday. This known issue specifically affected users who had not installed the necessary Microsoft Store updates on ARM devices, such as the Surface Pro 11 and Surface Laptop 7, running Windows 11 24H2 or later. Microsoft reported that the problem manifested as Teams and the new Outlook potentially failing to launch or closing unexpectedly on these ARM-based systems, noting that classic applications like Outlook, Word, and Excel were not known to be impacted. The issue was primarily likely to occur on systems that had not yet completed the installation of relevant Microsoft Store updates. As a temporary measure, Microsoft suggested that affected customers update the Auto Super Resolution Package, which is designed to enhance gameplay smoothness on Copilot+ PCs. The definitive fix was delivered through cumulative updates, specifically KB5124012 and subsequent updates released after September 8, 2026, which resolved the underlying bug. The article contextualizes this fix within a broader set of updates released in August 2026, which included other fixes such as resolving issues with the .NET Framework breaking printing and PDF exporting in applications utilizing the Windows Presentation Foundation UI framework, and addressing system crashes related to peripherals with built-in RGB lighting on Windows 11 systems. Furthermore, Microsoft addressed issues concerning Microsoft Defender Antivirus alerts following the August updates and resolved problems where custom mouse and Windows desktop settings were wiped on some Windows 11 systems after installing the KB5120998 preview update.