Child actors not appearing in PIE - World Partition - 5.6

Hello,

Since we upgraded to 5.6, we’ve had various child actors disappear when playing in editor. The actors do appear and work properly in a packaged build. We’re using Iris and world partition in these levels and it only appears to affect actors with replicated child actor components within a level instance in the main project. The provided reproduction project however also has the same issue for actors placed directly in the level. The child actors are generated at editor time through a commandlet from data assets, which I’ve somewhat mimicked in the test project by having an editor function that spawns the component with similar code we have. Doing the same with a blueprint editor callable function does not cause the same issue.

I’ve been able to fix this issue by restoring some child actor specific handling code that was removed in the 5.6 update. Specifically the editor only changes in WorldPartitionLevelHelper.cpp submitted in this changelist:

https://github.com/EpicGames/UnrealEngine/commit/723ba584d1fd69bcb8f39e05040b3945eadbf8bb\#diff\-908f796003833d4c33225f2e970d5091f2848fb6df28d48b00e62b65406f53cc

We’re a bit reluctant to restore code specifically removed in a changelist regarding child actor components so I wanted to double check if this is the proper way to resolve the issue or if there’s another fix/workaround for this issue.

Thanks,

Mathias

Steps to Reproduce
In the provided testmap:

1) Start PIE as client, server under one process

2) Observe the child actor (white cube) doesn’t appear in PIE

Thanks for reporting this one, Mathias. A fix has been submitted in main at CL 45148913.