Level saving bug, Graph is linked to external private object GEN_VARIABLE.PhysicsSerializer (PhysicsSerializer)

Steps to recreate:

  1. create new project with starter content

  2. create new BP_CustomInstancer blueprint, that is inherited from InstancedStaticMesh component

  3. create BP_CustomActor actor blueprint, and add BP_CustomInstancer to it

  4. Add BP_CustomActor to level, and save.

  5. Set default StaticMesh for BP_CustomInstancer inside BP_CustomActor blueprint, apply and save.

  6. 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

Hello Dmitriy_Filipchuk,

I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have also provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-42144)

Make it a great day

Hi, thanks. I think you specified engine version incorrectly, this bug exists at least from 4.13 onward, up to latest 4.15.0

In 4.16 the same error