CERT24Microsoft fixes Teams and Outlook launch failures on ARM-based Windows PCsLoading data…
CERT24Threat Observatory
Period

Microsoft fixes Teams and Outlook launch failures on ARM-based Windows PCs

Microsoft fixed an issue that could prevent Teams and the new Outlook from launching or cause them to close unexpectedly on ARM-based Windows devices after installing Windows security updates released on or after August 11, 2026, including KB5121003. The issue primarily affected devices running Windows 11 version 24H2 or later that had not yet installed Microsoft Store updates.

← Back to intelligence

Microsoft fixes Teams and Outlook launch failures on ARM-based Windows PCs

Microsoft fixed an issue that could prevent Teams and the new Outlook from launching or cause them to close unexpectedly on ARM-based Windows devices after installing Windows security updates released on or after August 11, 2026, including KB5121003. The issue primarily affected devices running Windows 11 version 24H2 or later that had not yet installed Microsoft Store updates.