Microsoft fixed a bug that caused Microsoft Teams and the new Outlook for Windows to fail to launch or close unexpectedly on ARM-based Windows 11 devices after August 2026 updates. The issue was resolved in September 2026 Patch Tuesday updates, with Microsoft advising users to install KB5124012 or later and apply Microsoft Store updates if needed. #MicrosoftTeams #Outlook #SurfacePro11 #SurfaceLaptop7 #KB5124012
Keypoints
- Teams and new Outlook were affected on ARM-based Windows 11 devices after August 11, 2026 updates.
- The issue mainly impacted devices without recent Microsoft Store updates.
- Classic Outlook, Word, Excel, and other apps were not affected.
- Microsoft suggested updating the Auto Super Resolution Package as a temporary workaround.
- The bug was fixed in the September 8, 2026 update KB5124012 and later updates.