Microsoft's Windows 11 26H2 has picked up a known audio issue within weeks of release, related to AC-3 (Dolby Digital) decoding. The bug can crash applications or prevent them from starting. It also affects Windows 11 25H2 and 24H2, which share the same code branch.
The problem was identified after the September 22 Windows update. Microsoft says it mostly impacts older applications that use Windows' built-in audio decoding; modern apps that bundle their own decoding components should be unaffected. Affected software can include games, media players, and certain productivity applications.
There is no fix yet, and uninstalling the update is the only current remedy. Microsoft says it is working on a resolution for a future Windows update. The AC-3 issue adds to existing audio problems in 26H2 and follows September Patch Tuesday troubles that required an out-of-band update for RDP and Hyper-V issues.