Windows 11 KB5124010 update crashes Dolby Digital audio apps

Microsoft has acknowledged a critical issue with the KB5124010 preview update for Windows 11, released on September 22, 2026. The update can cause crashes in games, media players, and productivity apps that use Dolby Digital (AC-3) audio decoding. The problem affects Windows 11 versions 26H2, 25H2, and 24H2, but not Windows Server. Microsoft identified the issue on October 2, 2026, and plans to release a fix in a future update.

The crashes occur when affected programs attempt to use AC-3 decoding, either at launch or while playing audio. The issue primarily impacts legacy software that relies on Windows' built-in audio decoding, as modern apps typically include their own components. Microsoft has not provided a list of affected applications.

KB5124010 is an optional preview update, so most users must manually install it. However, devices running Windows 11 version 24H2 with the "Get the latest updates as soon as they're available" option enabled will receive it automatically. Microsoft has not offered a workaround or rollback, advising users to avoid the update if they rely on older software.

This issue follows another audio-related problem in September's releases, where some USB Audio Class 1.0 devices failed to function properly. Microsoft has not specified when the fix for the Dolby Digital crashes will be available, leaving users uncertain if it will arrive with the October Patch Tuesday release.