Overview
- Microsoft confirmed on Monday that the September preview update KB5124010 can make applications that use AC-3 audio decoding fail to launch or close unexpectedly.
- The bug affects Windows 11 versions 24H2, 25H2 and 26H2 and mainly harms older programs that rely on Windows’ built-in Dolby Digital decoder while most modern apps that ship their own decoder are unlikely to be affected.
- KB5124010 is labeled optional but can install automatically on systems with the “get the latest updates as soon as they are available” setting, and removing the preview usually ends the crashes but in some cases rollback attempts produced boot failures that required clean reinstalls.
- Microsoft says it is working on a resolution and will deliver a fix in a future Windows update but it has not provided a timeline or workaround.
- This AC-3 crash is a separate audio regression following other September problems such as USB audio failures and Remote Desktop or Hyper-V regressions, a pattern that forces users and IT teams to balance urgent security updates against system stability.