Microsoft Windows update crashes games and apps with AC-3 audio decoding

Microsoft has acknowledged a new issue affecting some games and applications following the release of the September 2026 KB5124010 Windows 11 preview update. The problem occurs when apps using AC-3 (Dolby Digital) audio decoding crash after installing the update. KB5124010 is an optional update, but it installs automatically on devices running Windows 11 24H2 if the "Get the latest updates as soon as they're available" setting is enabled.

According to Microsoft, affected applications may include games, media players, and certain productivity apps. In some cases, the apps fail to launch or close unexpectedly, while in others, they function normally until specific features, like playing music, are used. The company noted that many modern apps are unaffected because they do not rely on Windows for this type of encoding and instead use their own audio decoding components.

Microsoft is working to resolve the issue but has not provided an estimated timeline for a fix. The company stated it will share more information in a future update. This is not the first time Microsoft has encountered audio-related issues with Windows updates. Last month, emergency updates were released to fix USB audio problems, Remote Desktop Services failures, and Hyper-V issues caused by the September 2026 security updates.

In the past, Microsoft has addressed similar audio playback issues and Code 10 errors on Windows 11 24H2 systems with USB audio device drivers. The company also previously blocked Windows 24H2 upgrades on systems with incompatible Intel Smart Sound Technology (SST) audio drivers due to blue screen of death (BSOD) issues.