InstancedStaticMeshComponent Failed Physics Serializer

When I open my project, I get an error from an Instanced Static Mesh Component being added in the construction graph of my actor.

What does this mean?

Can someone move this to bug report? I feel it may have more chance of finding an answer there.

@Adam Davis
Not sure if this is how I notify someone?

This thread may have your answer [4.8 P3] PhysicsSerializer Errors on Project Startup - World Creation - Epic Developer Community Forums, it was a matter of just unlinking the nodes and reconnecting them.

Similar issue on trying to save the project in UE 4.10.4: I have a Blueprint inherited from StaticMashActor. Added an InstancedStaticMeshComponent as a component. Level can be saved if the actor is not on the level. After placing such an actor to the level and trying to save it I get:

Can't save D:/UE/Projects/Assembly2/Content/RollingBP/Maps/RollingBPExampleMap.umap: Graph is linked to private object(s) in an external package.
External Object(s):
PhysicsSerializer
  
Try to find the chain of references to that object (may take some time)?

The above link is broken. Correct link without the trailing comma:
https://answers.unrealengine.com/questions/231275/physicsserializer-errors-on-project-startup.html