Following the recent Patch Tuesday update, KB5121003, a number of users have encountered significant challenges with Microsoft Teams and New Outlook on ARM64 devices, such as the Surface Laptop 7, Surface Pro 11, and HP OmniBook 3. As of now, Microsoft has not acknowledged this issue on its Windows 11 health dashboard, leaving many hopeful for a forthcoming investigation.
Details of the Issue
Reports indicate that while traditional Win32 applications like Classic Outlook, Word, and Excel remain unaffected, the modern MSIX and AppX apps are experiencing startup failures. Users have noted that reverting to the previous update, KB5121003, restores functionality. However, attempts to resolve the issue through recovery options like DISM, SFC, and even factory resets have proven ineffective once the problematic patch is reapplied.
Brian Stringfellow, the first to report the issue, has delved into system logs and identified that the root cause appears to stem from broken AppModel Runtime package states rather than profile corruption. His findings suggest that after the installation of the latest update, the affected applications encounter dependency issues, resulting in 0x80073CFC errors during token generation. Stringfellow also pointed out that this flaw mirrors a similar issue experienced earlier this year with update KB5094126, which similarly hindered the launch of Teams and New Outlook.
This situation underscores the challenges associated with Microsoft’s transition from legacy Win32 software to MSIX web apps. These modern applications rely heavily on essential Windows components, such as MicrosoftWindows.Client.CBS, and a single dependency failure can render critical enterprise software inoperable.
While some users have attempted to create new Windows profiles as a workaround, this solution has only provided temporary relief, as the issue re-emerges upon rebooting the system. Until Microsoft addresses this problem, it may be prudent for administrators to pause the deployment of KB5121003 on ARM devices, particularly if these applications are vital for daily operations.
