Microsoft confirmed over the weekend that some games and applications using AC-3 (Dolby Digital) audio decoding will crash after installing the September 2026 KB5124010 Windows 11 preview update.
KB5124010 is an optional update that requires users to click the "Download and install" link, which should reduce the number of potentially affected Windows users. However, it installs automatically on devices running Windows 11 24H2, where the "Get the latest updates as soon as they're available" option is toggled on.
"In some cases the application can fail to launch, or close without warning. In other cases the application will work normally until certain features are used, such as playing music," Microsoft said in a Friday update to the Windows release health dashboard. "Affected applications may vary and can include games, media players, and certain productivity applications."
However, the company added that many modern apps don't use Windows for this type of encoding and aren't affected. Additionally, the code component that triggers these crashes is most commonly used in legacy applications that still use the Windows built-in audio decoding, while modern apps that use the legacy AC-3 codec often include their own audio decoding components.