Microsoft fixes game, app crashes caused by recent Windows update

The September 2026 Windows 11 preview update KB5124010 introduced a bug causing crashes in games and applications that use AC-3 (Dolby Digital) audio decoding via Windows' built-in codec. Affected applications could fail to launch or close unexpectedly, especially when playing audio content encoded with AC-3. Many modern apps that use their own audio decoding components were not impacted. Microsoft acknowledged the issue and released the KB5127648 update in October 2026 to fix the problem on Windows 11 24H2 and later versions.

The bug caused affected games and applications to crash or fail to launch, disrupting user experience and functionality related to AC-3 audio playback. This impacted media players, games, and productivity apps relying on Windows' native AC-3 decoding. However, the issue was limited to systems that installed the optional KB5124010 preview update or had automatic updates enabled for early releases. No evidence of exploitation or security compromise was reported.

Microsoft has released an official fix in the October 2026 Patch Tuesday update KB5127648. Users experiencing crashes with AC-3 audio decoding should install this update on Windows 11 24H2 and later systems. Since KB5124010 is an optional preview update, users who have not installed it or have automatic updates disabled are less likely to be affected. No additional mitigation actions are required beyond applying the official patch.