'TSubobjectPtr::operator =' : cannot access private member declared in class 'TSubobjectPtr'

yup.i can do anything but assigning any other value.

For example,this also failed with same error:

 FString testSong = TEXT("SkeletalMesh'/Game/GenericMale.GenericMale'");
 static ConstructorHelpers::FObjectFinder myAssetForTP(*testSong);
 if (myAssetForTP.Succeeded())
 Mesh = (USkeletalMeshComponent*)myAssetForTP.Object;

any help with assignment method?