Microsoft: KB5124010 Preview Update Crashes Some AC-3 Audio Apps
Microsoft says the optional September 2026 Windows 11 preview update can crash games, media players and productivity apps that use AC-3 (Dolby Digital) decoding.
Microsoft has confirmed that some games and applications that use AC-3 (Dolby Digital) audio decoding will crash after installing the September 2026 KB5124010 Windows 11 preview update, according to bleepingcomputer.com.
The company said affected software may include games, media players and certain productivity applications. The failure is tied specifically to AC-3 decoding, not to audio playback in general.
KB5124010 is an optional preview update: it installs only when a user clicks the "Download and install" link. On devices running Windows 11 24H2 with the "Get the latest updates as soon as they're available" option enabled, however, it downloads and installs automatically.
Microsoft said it is working to resolve the issue and will share more information in a future update. The company has not given a timeline for a fix or named the specific applications affected.
Earlier audio fixes in Windows 11
The issue follows a run of audio-related Windows 11 problems. In September 2026, Microsoft released emergency updates to fix USB audio issues, Remote Desktop Services failures and Hyper-V problems that appeared after the KB5124008 and KB5124012 security updates. In January 2025, the company addressed an issue that triggered audio playback problems and Code 10 errors on Windows 11 24H2 systems with USB audio device drivers, and lifted a safeguard hold that had blocked upgrades on systems where Bluetooth headsets and speakers malfunctioned because of Dirac audio improvement software.
Quick answers
Which Windows 11 update is causing the AC-3 audio crashes?
Microsoft says the September 2026 KB5124010 preview update causes crashes in some games and applications that use AC-3 (Dolby Digital) audio decoding.
Will KB5124010 install automatically?
It is an optional update that requires clicking "Download and install," but it installs automatically on Windows 11 24H2 devices with the "Get the latest updates as soon as they're available" option enabled.
Is there a fix for the KB5124010 crashes yet?
Microsoft says it is working to resolve the issue and will share more information in a future update. No timeline has been given.