- I have several models in a .udatasmith file
- After import, I use “convert selected components to blueprint class”
Now I want to update some of my models…
- Regardless if I use Datasmith or Dataprep, the entire scene is re-spawned in the level
- Now I have to delete it every time and ignore these “break reference” warnings.
- Also, in my blueprint actors, meshes not present in the update remains, which means they’re not cleaned out from the content folders either.
It’s a super annoying workflow! 
EDIT: Just now also discovered that despite me attempting to clean out static meshes that I removed, I still get this BUT ONLY ON A SHIPPED PACKAGE of my project…

EDIT: Ok, so I just deleted all datasmith imports (except the dataprep asset), cleared out all datasmith actors and static meshes from my blueprints, re-imported everything again, and re-did the whole convert to blueprint and copy components dance detailed above, and still I get this…
LowLevelFatalError [File:Unknown] [Line: 2598]
Missing import of (/Game/CRPG/Levels/Dungeon/Sewers): DatasmithActorTemplate_51 in Package /Game/CRPG/Blueprints/Tiles/Dungeon/CellarCorner was not found, but the package exists.
It seems that Datasmith/Dataprep imported geometry and actors, converted to Blueprint actors, can’t handle being copy pasted into existing Blueprint actors with custom classes? That’s quite a limitation if so…
EDIT: This seems to be a blueprint nativization bug! Possibly (since I’ve talked to folks and I see other issues popping up as well) related to this, although I’m still seeing it in preview 6…