Unreal 4.26/4.27 + ios15 = no audio on resume

Our project on iOS 15 stops playing sound after being restored from the running in the background for more than 5 seconds or so. This happens in our existing project, but also happens on the off-the-shelf side scroller project in Unreal - after attaching a sound to a “jump” action on the character. This issue does not happen on iOS 14 or lower.

Interestingly enough, the Unreal Match 3 sample game available in the store exhibits the exact same behaviour. Has anyone else experienced this and/or have any hints for resolution?



This is a pretty terrible issue. You leave the app and come back and the audio doesn’t work anymore until the level is reset.

This seems to be an issue with iOS 15. My old app that’s been on the store for 2 years has this issue too on iOS 15.

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I filed a bug with Unreal when I first posted, but no response from them. I’ve since ported all our audio to use FMOD. Problems are gone - use their audio engine instead of Unreal’s.

@smg-stang do you have a link to the bug so I can track that? I am seeing this issue as well. Thanks!

Sorry, no bug number - I submitted the bug on Sept 22 and only got this:

Thank you for your bug submission. We will review your case and will follow up if more information is needed or a ticket is created. In the event the issue you reported is scheduled for a future release or has known workarounds, you may not receive a follow-up message from our team. 

You can track the latest UE4 issues at https://issues.unrealengine.com/ 

This is an automated response. Please do not reply to this email. 

Thank you, 
Epic Games

…no reply since and no sight of it on https://issues.unrealengine.com

Also seeing this bug, really ridiculous that they let something like this slip

@VictorLerp any info on this bug? Maybe it has been fixed in 5.0?

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A work around or fix that doesn’t require using a 3rd party audio solution would be great.

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Hello everyone.

iOS 15 got released after 4.27 Release so QA did not see this issue.

We have looked into it and found out AVAudioSessionInterruptionTypeKey behavior has changed in iOS15, so we stopped relying on it altogether to make sure sound works on all iOS versions.

I have tested the change on iOS13.5 and iOS15.1 with a template project and it works as expected, but please understand QA has yet to make a pass on this code so I cannot attest of its reliability for now.
We are trying to get it in 4.27.2.

If you want to merge it to your current engine, here is a patch that needs to be applied to

DiffReport.patch (458 Bytes)

Here are scren caps of it in case you want to merge “a la mano”

I am very sorry for the wait, and tell me if it fixes your sound issue !



Thank you. This appear to be in the latest launcher also. Working great as far as I can tell.