Windows 11 Update KB5124010 Breaks Dolby Digital Audio - Here's the Fix

A Windows 11 update from late September is making some games and media players crash the moment they try to play Dolby Digital sound.

Microsoft has confirmed the bug, traced it to update KB5124010, and says a fix is coming in a future update - but there is no date yet.

The quickest way around it today is a media player that brings its own Dolby decoder, so the broken Windows one never gets a say.

Here is what broke, who is hit, and what to do about it.

What Broke, in Plain English

AC-3 is the technical name for Dolby Digital, the surround sound format used on DVDs, TV recordings and a lot of downloaded films. Windows includes its own AC-3 decoder - the small part that turns that audio into sound your speakers can play.

KB5124010, released on 22 September 2026, broke that decoder. Microsoft says apps that rely on it "might close unexpectedly" - some refuse to open at all, others run fine until the moment they start playing audio.

Who Is Affected

• Windows versions: Windows 11 24H2, 25H2 and 26H2 - Windows 10 is not on Microsoft's list.
• Apps: older games, older media players and some office-type programs that still ask Windows to decode Dolby audio - Microsoft has not named any.
• Not affected: most modern apps, which carry their own audio decoder and never touch the Windows one.

The tell is timing. If a program crashes exactly when sound starts - a cutscene, a menu with music, the first second of a film - and it began after late September, this bug is the likely cause.

Microsoft also says the problem affects KB5124010 "and later" updates. Expect it to reach many more PCs with the regular 13 October update, unless the fix lands first.

Fix It Today: Use a Player With Its Own Decoder

This is the cleanest fix, because you keep every Windows update and every security patch. These free players decode Dolby Digital themselves, so the bug simply does not reach them:

• VLC Media Player - plays almost any file with nothing else to install.
• MPC-HC - small, fast and ad-free, with the LAV decoders built in.

MPC-BE and PotPlayer also carry their own decoders, if you already use one of those.

Stuck with an older program you cannot swap out? The K-Lite Codec Pack installs LAV Audio, a modern Dolby decoder that many older Windows players will use instead of the built-in one. It will not rescue every game, though, because some talk to the Windows decoder directly.

Option Two: Remove the Update

If a game you play every day keeps crashing, removing KB5124010 should stop it. Microsoft has not offered a workaround of its own, so this is the only way to undo the change.

1. Open Settings > Windows Update > Update history.
2. Scroll down and choose Uninstall updates.
3. Find KB5124010 in the list, choose Uninstall, then restart.
4. Back in Windows Update, use Pause updates so it does not reinstall straight away.

On Windows 11 24H2 there is an extra wrinkle - Home and Pro editions get their last update on 13 October 2026. Moving to 25H2 or 26H2 keeps the security updates coming.

When Will Microsoft Fix It?

Microsoft lists the issue as Confirmed and says a fix will come in a future Windows update, with no date given. The next regular update is due on 13 October, but nothing says the fix will be in it.

You can follow it on Microsoft's Windows release health page, where the entry is titled "Applications which require AC-3 audio decoding might close unexpectedly".

Quick questions