Is New Outlook & Teams Not Launching on ARM64 PCs After Windows 11 KB5121003 Update? Microsoft Shares a Temporary Fix

In addition to confirming mouse curor and desktop customization issues, Microsoft also issued a temporary fix for another Windows 11 issue affecting Teams and new Outlook on ARM-based PCs following August 2026 Patch Tuesday KB5121003 update. The apps may refuse to launch or suddenly close after recent security updates.

Teams and Outlook launch issue hit Windows 11 users on ARM64 PCs

The issue was triggered by Windows security updates released on or after August 11, 2026. Microsoft lists KB5121003 as the originating update for the problem. Affected devices include ARM-based PCs such as Surface Pro 11 and Surface Laptop 7. Classic Outlook, Word, Excel, and other applications are not known to be affected.

Microsoft says the problem is more likely on new or freshly set up PCs. These systems may not have installed Microsoft Store updates yet. That detail points users toward a specific workaround instead of reinstalling the affected applications. Microsoft currently lists the issue as mitigated.

Microsoft Store is involved in a possible workaround shares by the company

In an update shared on Windows Release Health Dashboard, Microsoft has urged affected users to open Microsoft Store and select Downloads. They can then choose Check for updates and install available updates. Microsoft specifically recommends installing the latest Auto Super Resolution Package. The package should be version 1.0.19.0 or later.

Once that update is installed, Teams and new Outlook should be able to launch normally. Microsoft has not suggested reinstalling Windows as part of its workaround.

A permanent fix for the issue will be released soon

The company says it is working on a permanent resolution through a future Windows update. Microsoft will provide more information when that fix becomes available. Do note that the issue affects Windows 11 users on versions 26H1, 25H2, and 24H2.