failed to build

Hi when i build i get this fatal error:Program.Main: ERROR: AutomationTool terminated with exception: AutomationTool.AutomationException: Cook failed. —> AutomationTool.AutomationException: BUILD FAILED: Failed while running Cook for C:\Users\Documents\Unreal Projects\Blacksmith 4.15\Blacksmith.uproject; see log C:\Users\AppData\Roaming\Unreal
Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.15\Cook-2017.03.13-19.41.18.txt
inside the txt file:
LogWindows:Error: ArrowComponent /Game/SceneCaptures/BP_CharacterRecorder.Default__BP_CharacterRecorder_C:Arrow was an archetype of ArrowComponent /Game/Map/starting_map.starting_map:PersistentLevel.BP_CharacterRecorder_554.Arrow but returned a null index mapping the object.

looks to be about my character’s arrow i the scene capture created for my equipment widget.

I deleted the arrow and it worked!