Steps to recreate:
create new project with starter content
create new BP_CustomInstancer blueprint, that is inherited from InstancedStaticMesh component
create BP_CustomActor actor blueprint, and add BP_CustomInstancer to it
Add BP_CustomActor to level, and save.
Set default StaticMesh for BP_CustomInstancer inside BP_CustomActor blueprint, apply and save.
Now set default StaticMesh just for BP_CustomInstancer alone, hit apply and save.
Now, when saving level with BP_CustomInstancer in it, i get the following error
After hitting yes, i get the following error:
Warning Can’t save …/…/…/…/…/…/Workspace/MyProject/Content/StarterContent/Maps/Minimal_Default.umap: Graph is linked to external private object PhysicsSerializer /Game/BP_CustomActor.BP_CustomActor_C:BP_CustomInstancer_GEN_VARIABLE.PhysicsSerializer (PhysicsSerializer)
File->Refresh nodes doesn’t help, the only way i can save level after this is to remove all instances of BP_CustomActor from it.
This is a showstopper for me =/
The bug also exists in 4.13.2