We recently started to make use of the new Quartz subsystem in our game, to support an interactive music system. This is working very well in development builds (editor or packaged), but we are now experiencing a complete loss of audio in our packaged Test and Shipping builds, which appears to relate to Quartz. Additionally, we are unable to exit the game without waiting indefinitely for an audio thread to terminate.
Having played around with the blueprint that our sound designer put together from Dan’s tutorial videos it seems that the audio drop-out occurs when the Create New Clock node runs. Disabling further use of the system makes no difference and it appears this node alone is causing problems. Given the loss of all sound and the hang on exit, I wonder if an audio thread has become deadlocked.
We’re running 4.26 and I’ve looked at a couple of relevant CLs on GitHub. The first, a fix for an audio render thread hang in Quartz, appears to have made it into 4.26. The other, a fix for modification of QuartzTickSubscribers, is in 4.26.1, so I’ve integrated this directly, but it did not have any bearing on this issue.
Has anyone else encountered this issue please? I would be grateful for any suggestions. In the meantime we will have to revert back to our old music system and defer our use of Quartz until we can resolve this.