Description

Attachment will currently fail at runtime during load and/or construction if a component from a non-nativized child Blueprint is attached to an inherited component from a parent class that is nativized.

Steps to Reproduce
  1. Launch UE4 editor with a new, blank BP-only project.
  2. Create a new Actor-based Blueprint class (BP_Parent).
  3. Double-click to open in the Blueprint editor, and add a new scene component (CompA), replacing DefaultSceneRoot.
  4. Add another new scene component (CompB) and attach it to CompA.
  5. In Class Settings, tick the "Nativize" option.
  6. Compile, save and close the Blueprint editor.
  7. Right-click BP_Parent and choose to create a child Blueprint class (BP_Child).
  8. Double-click to open in the Blueprint editor, and add a new scene component (CompC). Attach CompC to CompA.
  9. Compile, save and close the Blueprint editor.
  10. Drag an instance of BP_Child into the current level and save the map (NewMap).
  11. Choose Editor->Project Settings... and in Maps and Modes set the game map to NewMap.
  12. In Packaging settings change Blueprint Nativization Method to "Exclusive."
  13. Choose File->Package Project->Windows->Win64, choose a location and wait for packaging to finish.
  14. Navigate to the game EXE and double-click to launch.
  15. Navigate to the "Saved" folder and double-click the log to open. Note the following warning about failed attachment:
[2018.05.30-17.17.28:554][  0]LogBlueprint: Warning: USimpleConstructionScript::FixupRootNodeParentReferences() - Couldn't find inherited parent component 'CompA' for 'CompC' in BlueprintGeneratedClass 'BP_Child_C' (it may have been removed)

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Won't Fix
ComponentUE - Gameplay - Blueprint
Affects Versions4.184.19
CreatedMay 30, 2018
ResolvedJul 15, 2021
UpdatedJul 19, 2021