When enabling the AudioDeviceModuleName=AudioMixerXAudio2 setting in the windowsengine.ini file it causes new level loads to lock up.


This may be due to the garbage collection stuck in a loop waiting for the mediasoundcomponents to be ready to delete. As the audio buffering is carrying on at this point, they never get set to ready to delete for long enough.

Steps to Reproduce

Sample project and .ini file provided.

In order to get this to reproduce properly first change the WindowsEngine.ini file located in Uengine\UE_4.19\Engine\Config\Windows

on the top in the [Audio] section comment out AudioDeviceModuleName=XAudio2

Then remove the comment from the new AudioDeviceModuleName=AudioMixerXAudio2


  1. Create a Third person c++ project 
  2. Create an empty C++ class (used for debugging)
  3. Create an actor Blueprint containing 8 mono mediasoundcomponents
  4. Add the actor to the level 
  5. Set up a key press/mouse click to open level in game instance (I used right click)
  6. Run the game in a new window and trigger the open level in game instance.
  7. Editor locks up requiring a force close.


Have Comments or More Details?

There's no existing public thread on this issue, so head over to AnswerHub just mention UE-55700 in the post.

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Affects Versions4.194.20
Target Fix4.21
Fix Commit4047083
CreatedMar 1, 2018
ResolvedMay 4, 2018
UpdatedAug 6, 2018