Users of Windows 11 26H2, 25H2, and 24H2 are experiencing audio playback issues following the recent September security update. The failure is linked to the system AC-3 Dolby Digital audio decoder, which causes applications relying on this component to crash or fail to launch entirely.
Microsoft confirmed that the bug primarily affects legacy software, including older games, media players, and specific professional tools. Modern applications are largely unaffected as they typically utilize their own encoding methods rather than relying on the built-in Windows audio decoding tools.
The issue was exacerbated by a preview update released on September 22. While Microsoft previously issued emergency patches for RDP and Hyper-V vulnerabilities following the Patch Tuesday release, a permanent fix for the AC-3 codec error has not yet been developed.
The audio bug is currently listed among the known issues for Windows 11 26H2. Microsoft has acknowledged the situation and stated they are working on a resolution for a future update, though the company has not provided a specific timeline for when the fix will be deployed.
