An older game, a media player or another program closes without warning on Windows 11, at launch or as soon as it plays sound? If the problem started in late September 2026, it may be a bug acknowledged by Microsoft, linked to the AC-3 (Dolby Digital) audio decoding built into Windows. Microsoft fixed it with the October 13, 2026 update. This guide helps you check whether you are affected, then install the fix.
Problem
- A game or app closes with no message, at startup or when playing music or video.
- The problem appeared after a Windows 11 update installed in late September or early October 2026.
- It mostly affects older programs, while recent apps work.
What to know first
- Update involved: update KB5124010 of September 22, 2026 (optional preview update for Windows 11 24H2, 25H2 and 26H2), and the following updates until the fix.
- Fix: Microsoft states that the issue is resolved by updates released on or after October 13, 2026, i.e. KB5127648.
- Affected apps: according to Microsoft, they can include games, media players and some productivity apps. The component involved is mostly used by older applications that still rely on Windows' built-in audio decoding. Many recent apps include their own decoder and are not affected.
- Windows 10 is not affected by this bug, according to Microsoft's dashboard.
Step 1: check the installed updates
When to use it: first.
Suggested solution
- Open Settings > Windows Update > Update history.
- Under Quality Updates, find the September and October 2026 updates.
- If KB5124010 is listed, without KB5127648 or a more recent update, you are probably affected.
Expected result: you know whether your PC received the update involved, and whether it already has the fix.
When to stop: if KB5127648 or a more recent update is already installed and the app still closes, the cause is elsewhere. Go to the special cases.
Step 2: install the October 2026 fix
When to use it: the September 22 update is installed, but not the October 13 one.
Suggested solution
- Open Settings > Windows Update.
- Click Check for updates.
- Install the security update offered (KB5127648, or a more recent cumulative update).
- Restart the PC.
- Launch the game or app again, then test the feature that caused it to close (music, video, cutscene).
What it does: according to Microsoft, the October update fixes the AC-3 audio playback issue in the affected apps.
Expected result: the app no longer closes when it plays sound.
Rollback: an update can be uninstalled from Update history > Uninstall updates. In this case, removing the fix would bring the bug back: it is not advised.
Special cases
- The update is not offered: Microsoft specifies that, for Windows 11 24H2 and 25H2, an update released on or after June 10, 2025 (for example KB5060842) must already be installed. Install pending updates first, then check again.
- The fix is installed, but the app still closes: this is probably not this bug. Check whether the software publisher offers an update, and note any error message in Event Viewer (Windows Logs > Application).
- Company-managed PC: updates may be delayed by the administrator. Report the problem to them.
Final check
- ☐ KB5127648 or a more recent cumulative update appears in the history.
- ☐ The PC restarted after installation.
- ☐ The game or app no longer closes when playing sound.
Sources
- Microsoft Learn: Windows 11, version 24H2 known issues and notifications (AC-3 issue)
- Microsoft: KB5124010, September 22, 2026 update
- Microsoft: KB5127648, October 13, 2026 security update
Still having the problem?
Reply with your Windows version (Windows + R, then winver), the name of the game or app, exactly when it closes and the latest update shown in the history. Do not post any account information or licence key.