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Apps closing or no sound after the September 2026 Windows update?

By the Brightfix team. Updated October 7, 2026. Applies to Windows 11 24H2, 25H2 and 26H2, Home and Pro. The USB audio issue also affects Windows 10 22H2.

Quick answer

Two known Windows 11 issues cause this. Apps that need AC-3 (Dolby Digital) audio may close after update KB5124010, with no fix yet, and some USB audio devices show Code 10 after the September 8 update, which Microsoft has partly fixed.

Before you start

  • Create a restore point before you remove any update, so you can go back if something else breaks.
  • Write down which app closes or which device goes silent, and when it started. It makes the next steps faster.
  • Do not remove the September 8 security update (KB5124008). Install the newer updates instead.
  • Pausing updates is a short-term step. Turn updates back on once Microsoft ships a fix.

1Check which September updates you have

Both issues are tied to specific updates, so first confirm which ones are on your PC.

  1. Open Settings > Windows Update > Update history.
  2. Open the Quality updates list.
  3. Look for KB5124010 (September 22, an optional preview update). This is the one tied to apps closing.
  4. Look for KB5124008 (September 8, security update) and KB5129195 (September 14, a fix for USB audio).
  5. To see your Windows version, open Settings > System > About and read Version under Windows specifications.
What you should see

A list of updates with their install dates. You can now match the date the problem started to an update.

If it did not work: If the list is empty or will not open, restart the PC and try again. If KB5124010 is not listed, the AC-3 issue is probably not your cause.

Undo: Nothing to undo. This only looks.

2Check Device Manager for Code 10 on a USB audio device

If a USB headset, speaker or audio interface went silent, this shows whether it is the known Code 10 issue.

  1. Right-click the Start button and choose Device Manager.
  2. Open Sound, video and game controllers, then Audio inputs and outputs.
  3. Look for your USB audio device. A yellow warning sign means it has a problem.
  4. Double-click the device and read Device status on the General tab.
  5. If it says This device cannot start. (Code 10), you likely have the known issue.
  6. If sound works in stereo but fails in 7.1 or 3D audio, open Settings > System > Sound > More sound settings, select the device on the Playback tab, choose Configure, pick Stereo, then Next until Finish.
What you should see

The device status shows Code 10, or switching to stereo brings the sound back.

If it did not work: If there is no Code 10 and sound is still missing, unplug the device, plug it into a different USB port, and restart the PC.

Undo: To go back to surround sound later, repeat the Configure step and pick your original speaker setup.

3Install the latest updates and update the app

Microsoft's fixes arrive through Windows Update, and many newer apps do not use the Windows AC-3 decoder at all.

  1. Open Settings > Windows Update and select Check for updates.
  2. Install everything offered and restart when asked. On 24H2 and 25H2, this includes the USB audio fix from KB5129195 or a newer update.
  3. Open the app or game that keeps closing and check for its own update (in the app, the Microsoft Store, or the game launcher).
  4. Try the app again after the restart.
  5. Check Windows Update again after each monthly update. The next one is due October 13, 2026.
What you should see

Your PC says it is up to date, and the device or app works again.

If it did not work: As of October 7, 2026, Microsoft has not released a fix for the AC-3 issue. If a needed app still closes, see the next step.

Undo: Nothing to undo. Installing updates is the normal, safe state.

4Remove KB5124010 if an app you need keeps closing

KB5124010 is an optional, non-security preview update, so removing it can stop the AC-3 crashes until Microsoft fixes them.

  1. Create a restore point: press Start, type Create a restore point, open it, select Create, and give it a name.
  2. Open Settings > Windows Update > Update history.
  3. Scroll to Related settings and select Uninstall updates.
  4. Find the entry with KB5124010 and select Uninstall.
  5. Restart the PC when asked, then test the app.
  6. Pause updates for a short time (next step) so the same change is not installed again before the fix.
What you should see

KB5124010 is gone from the uninstall list, and the app stays open while playing audio.

If it did not work: If KB5124010 is not in the list, Windows may not allow removing it. On 26H2, this update (or a later one) is required for 26H2 itself, so waiting for Microsoft's fix is the better path there.

Undo: Go to Settings > Windows Update and select Check for updates to install it again, or use the restore point you made.

5Pause updates for a short time

Later cumulative updates include the same change, so a short pause keeps it off until Microsoft ships the fix.

  1. Open Settings > Windows Update.
  2. Next to Pause updates, choose a short pause, such as 1 week. The longest pause is 35 days (5 weeks).
  3. Check Microsoft's Windows release health page each week for a fix to the AC-3 issue.
  4. When the fix is out, select Resume updates and install everything offered.
What you should see

Windows Update says updates are paused until a date you chose.

If it did not work: If the pause option is greyed out, your PC is managed by work or school settings. Ask your IT team.

Undo: Select Resume updates in Settings > Windows Update.

IssueStarted withAffectsStatus on October 7, 2026
Apps that need AC-3 (Dolby Digital) audio close or will not startKB5124010, September 22, 2026 (optional preview), and later updatesWindows 11 24H2, 25H2, 26H2Confirmed. No workaround yet. Fix promised in a future update.
USB Audio Class 1.0 devices show Code 10 or play no soundKB5124008, September 8, 2026 (security update), and 26H2Windows 11 23H2 to 26H2, Windows 10 22H2Mitigated. KB5129195 (September 14) fixed the 8-channel and 3D audio part on 24H2 and 25H2. Other symptoms still being worked on.

Why this happens

AC-3, also called Dolby Digital, is a surround sound format. Some older apps and games ask Windows to decode it using a codec built into Windows. After the September 22, 2026 preview update (KB5124010), that built-in decoder can make those apps close or fail to start. Many modern apps ship their own decoder, so they are not affected. The USB issue is different. After the September 8 security update, the Windows driver for USB Audio Class 1.0 devices can fail to start, which Device Manager reports as Code 10. Microsoft fixed the multichannel part of that with an out-of-band update on September 14 and is still working on the rest.

Still stuck?

Which apps are affected by the AC-3 issue?

Microsoft has not published a list. It says games, media players and some productivity apps can be affected, mostly older ones that rely on the decoder built into Windows. If an app crashes only when it plays sound or video, and it started after September 22, this issue is a likely cause.

Is it safe to uninstall KB5124010?

KB5124010 is an optional, non-security preview update, so removing it carries less risk than removing a security update. Make a restore point first, and plan to install updates again once Microsoft releases the fix. Keep the pause short so you do not miss the October security update for long.

Will the October 13 update fix the AC-3 crashes?

Microsoft has not said when. Its release health page says a fix will come in a future Windows update. Later cumulative updates also contain the change from KB5124010, so if you removed it, check the release health page before you resume updates.

My USB headset still shows Code 10 after updating. What now?

Microsoft has only partly fixed the USB audio issue. Try a different USB port, restart, and switch the device to stereo if you use surround modes. If it still fails, a Bluetooth or 3.5 mm headset can be a short-term option until the remaining fix arrives.

Does this affect Windows 10?

The AC-3 issue affects only Windows 11 24H2, 25H2 and 26H2. The USB audio Code 10 issue is listed for Windows 10 22H2 and 21H2 as well as several Windows 11 versions. Check Update history and Device Manager the same way on Windows 10.

Related guides

How we checked this guide

Steps and update details checked against Microsoft's Windows release health pages and update notes on October 7, 2026. We have not reproduced the crashes on our own PCs. Screenshots coming soon.

Changes

  • October 7, 2026: First published.

Sources

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