When an actor is spawned with Spawn Parameters that are templated the engine crashes when closing a scene. This wasn't happening when there wasn't a physics constraint on the spawned blueprint.
This is similar to https://jira.it.epicgames.net/browse/UE-45206.
Found in 4.24.3 CL#11590370
Reproduced in 4.23.1 CL#9631420, 4.25.0 P1 CL#11723679, 4.26 Main CL#11724764
1. Create a C++ project.
2. Create a blueprint(DemoBP) with a static mesh component.
3. Add a physics constraint to DemoBP and set Component Name 1 to the name of the static mesh.
4. Create a C++ actor class (DemoActor).
5. In DemoActor spawn two instances of DemoBP in BeginPlay.
6. When spawning the second actor use the first one as a template in FActorSpawnParameters.
7. Place an instance of DemoActor in the scene.
8. Play the scene.
9. Stop the scene.
Result: The engine crashes.
Expected: The engine doesn't crash.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-90128 in the post.