How to get AttachedParent of UActorComponent?

I am trying to attach a sphere from my component, derived from UActorComponent, to the root of the Actor this component is attached to. I tried

MySphere->AttachTo(GetOwner()->GetRootComponent());

But when I compile the project it crashes. I think that GetOwner() returns null. So how can I attach my sphere to the actor, that my component is attached to?