problem loading assets in package

hi forum i have a issue with this

i have a class to instance a UStaticMeshComponent* and loads a mesh inside; editor works perfect but in package dont work
i evalute with FStringAssetReference i have no NULL mesh but dont display nothing, is this a bug?
this is my sample code of the constructor

	pivotComponent = CreateDefaultSubobject<USceneComponent>("Pivot");
	RootComponent = pivotComponent;

	plane= CreateDefaultSubobject<UStaticMeshComponent>("Plane");

#define LM_ASSETS_FOLDER TEXT("/Meshes")

	UStaticMesh* planeMesh = ConstructorHelpers::FObjectFinder<UStaticMesh>(LM_ASSETS_FOLDER TEXT("/Plane")).Object;
	if (plane != NULL)
		Plane->SetStaticMesh(planeMesh );
		//y = width, z = height
		Plane->SetRelativeScale3D(FVector(1, 640, 480));
		Plane->SetRelativeLocation(FVector(660, 0, 0));


and now in the begin play i find them

void AMyPawn::BeginPlay()
FStringAssetReference thePath = FStringAssetReference(Plane->StaticMesh);

	if (!thePath.IsValid())
		GEngine->AddOnScreenDebugMessage(-1, 10, FColor::Red, thePath.ToString());


is working and print the right path in package but is loading nothing! what is wrong here? i am overhelmet with this