BUG - blueprint with child actor crashes when trying to add to level instance in a world partition enabled world

Following the steps below will cause a immediate crash when trying to play a level with a level instance that contains a blueprint with a child actor. It seems to be that the child blueprint is loaded with the correct parent level name but the world’s do not match and it causes a crash.

Description

Repro steps:

  1. Create a blueprint (ex. “BP_WithChild”) based off the actor class

  2. Create a second blueprint (ex. “BP_SampleChild”) also based off the actor class

  3. Drag the second blueprint into the viewport hierarchy of the first blueprint, adding it as a child actor

  4. Open a world partitioned level , we’ll call it P_Worldmap

  5. Load the central world partition cells

  6. Create a new level instance with anything (like a static mesh).

  7. Save the level and click on a level instance and click edit in the details page

  8. Click Edit

  9. Drag your parent blueprint (“BP_WithChild”) into the level instance

  10. Right click, navigate to Level>Commit

  11. Play in editor

  12. 100% crash repro