StateMachineBehaviour.OnStateExit is called before StateMachineBehaviour.OnStateEntered is called

Question

When I start my game I get null-references in my OnStateExit of objects that are initialized in the OnStateEntered. After this it goes smooth, so it only occurs at startup before any conditions for statechanges are met.

How come? My understanding is that OnStateExit is always preceded by OnStateEntered.

My StateBehaviour

public class DuckStateBehaviour : BaseStateBehaviour {

    override public void OnStateEnter(Animator animator, AnimatorStateInfo stateInfo, int layerIndex) 
    {
        base.OnStateEnter(animator, stateInfo, layerIndex);
        mMovement.BeginDuck();
    }

    public override void OnStateExit(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
    {
        if (mMovement != null) mMovement.EndDuck();
        base.OnStateExit(animator, stateInfo, layerIndex);
    }
}

public class BaseStateBehaviour : StateMachineBehaviour {

    protected Transform mTransform = null;
    protected Rigidbody2D mRigidBody = null;
    protected IMovement mMovement = null;

    public override void OnStateEnter(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
    {
        mTransform = animator.gameObject.GetComponent<Transform>();
        mRigidBody = animator.gameObject.GetComponent<Rigidbody2D>();
        mMovement = animator.gameObject.GetComponent<IMovement>();

        Debug.Assert(mTransform != null);
        Debug.Assert(mRigidBody != null);
        Debug.Assert(mMovement != null);
    }

}

Answer 1

In case you have a transition, one state can start and the other can still be executing (updating): So yes, they can happen in the "wrong" way.