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Windows 11 26H2 Update Triggers AC-3 Audio Decoding Crashes
By Drooid · · How we work
New AC-3 Decoding Bug Affects Multiple Windows 11 Versions
Microsoft identified an audio-decoding flaw after the September 22 Windows update. The defect lies in the component that handles AC-3 (Dolby Digital) decoding and can cause applications that rely on this built-in decoder to crash or fail to start. The problem is present in Windows 11 24H2, 25H2 and the newly released 26H2 because all three share the same code branch.
Scope and Affected Software
According to Microsoft, the issue primarily impacts “legacy” applications—older games, media players and certain productivity tools that still depend on Windows’ native AC-3 decoder. Modern software that includes its own decoding library is generally unaffected. The company notes that most users are unlikely to encounter the bug, but for those whose apps use the built-in decoder, the only current remedy is to uninstall the optional September update (KB5124010) until a fix is issued.
Microsoft’s Response
Microsoft has publicly acknowledged the bug and confirmed that it is working on a resolution to be delivered in a future Windows update. No specific timeline has been provided, and the company has not released a mitigation or workaround beyond removing the problematic update.
Related Recent Update Issues
The AC-3 bug follows a series of audio-related problems introduced by September’s Patch Tuesday. An out-of-band update earlier in the month addressed Remote Desktop Protocol and Hyper-V issues but did not resolve all audio defects, and a separate issue involving broken USB audio remains unresolved.
Outlook
At present, the AC-3 decoding flaw remains unpatched, and Microsoft has indicated that a fix will arrive in a later update without specifying a release date. Users of affected legacy applications are advised to monitor Microsoft’s support channels for the forthcoming resolution.