Windows bug causes older apps and games to crash
Microsoft warns that programmes using Dolby Digital may close unexpectedly.
A known bug in recent Windows 11 updates can cause some older applications and games to crash. The problem affects programmes that use Windows’ built-in Dolby Digital or AC-3 decoder.
Microsoft lists the problem on the support page for update KB5124010, an optional preview update from 22 September 2026. The bug can occur on Windows 11 versions 24H2, 25H2 and 26H2. According to Microsoft, programmes that decode AC-3 audio may fail to start or close unexpectedly when certain audio features are used.
This is not a general crash of Windows 11. The notice concerns applications that depend on the system decoder for Dolby Digital. PCWorld writes that older programmes and games in particular appear to be vulnerable, while modern applications often use their own audio code. Microsoft has not disclosed exactly which programmes are affected.
The bug may become visible when changing the volume, switching audio settings or playing certain sound clips. As a result, a programme may initially work normally and only close later. According to Microsoft, the cause lies in the way the relevant audio code is shared across multiple Windows versions.
The notice is separate from other audio problems that Microsoft described in September. For example, some USB Audio Class 1.0 devices may no longer produce sound or may display error code 10 after an earlier security update. The Dolby bug, by contrast, concerns software that decodes AC-3 audio.
Microsoft says it is working on a fix that should be distributed through a future Windows update. At the time of writing, the support page did not give a definitive release date for the fix. Users experiencing the problem would therefore be wise first to establish which update and which application are involved, rather than installing arbitrary codecs from the internet.
The issue comes against the background of Microsoft’s changed codec policy. On new installations of Windows 11 24H2, AC-3 is no longer included by default, although manufacturers can pre-install the codec and it may sometimes remain after an upgrade. That earlier decision and the new crash notice are related to the same audio chain, but are not the same problem.
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The technical core can be found directly in Microsoft’s release information and is independently described by PCWorld. The text avoids issuing a universal warning and notes that older applications in particular appear to be affected.
- confirmed KB5124010 applies to Windows 11 24H2, 25H2 and 26H2. — Microsoft names these three versions on the update page. source
- confirmed Programmes that decode AC-3 audio may fail to start or close unexpectedly. — This is the known bug described by Microsoft and PCWorld. source
- confirmed Older applications in particular appear to be vulnerable. — PCWorld summarises Microsoft’s description as applying mainly to legacy applications. source
- confirmed Microsoft is working on a fix via a future Windows update. — PCWorld quotes Microsoft’s status notice. source
- confirmed AC-3 is no longer included by default on new installations of Windows 11 24H2. — Microsoft describes this change in its codec explanation. source
Editor's note
The error message and the affected Windows versions have been officially confirmed. The precise list of programmes and the date of the fix were not yet known.Sources
- September 22, 2026—KB5124010 Preview — Microsoft Support
- Microsoft confirms a second Windows 11 audio bug this month — PCWorld
- Troubleshoot Windows Media Player Errors — Microsoft Support
More on this in Dutch media
- NOS — „windows 11”
- Het Parool — „windows 11”
- NRC — „windows 11”