Microsoft Resolves Teams and Outlook Launch Failures on ARM Windows Devices

Microsoft has released a fix for a bug that prevented Microsoft Teams and the new Outlook for Windows from launching on ARM-based Windows devices.

The issue affected users running Windows 11 24H2 or later on ARM-based hardware, including the Surface Pro 11 and Surface Laptop 7. The bug was triggered by Windows security updates released on or after 11 August 2026 (KB5121003), causing the applications to either fail to launch or close unexpectedly.

Microsoft noted that the problem was most likely to occur on new or freshly imaged PCs that had not yet installed Microsoft Store updates. As a temporary workaround before the official fix, the company advised users to update the Auto Super Resolution Package, which supports AI-enhanced gameplay on Copilot+ PCs.

The bug has been resolved in the September 2026 Patch Tuesday cumulative updates. Users can address the issue by installing update KB5124012, which was released on 8 September 2026.

Classic versions of Outlook, Word, and Excel were not impacted by this issue. This development follows several recent Windows update complications, including .NET Framework bugs affecting printing and PDF exporting, as well as system crashes linked to RGB lighting peripherals.