AnimationClipPlayable second animation broke

Questions & Answers
1

I tried to change animation clips through AnimationClipPlayable.
But first animation only plays correctly.
Second animation broke.

This is reproduce code.
Is is a bug or my usage is wrong?

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.Experimental.Director;

public class PlayableTest : MonoBehaviour {

// reference
public Animator characterAnimator;

public List<AnimationClip> clips;
private int index = -1;

public void OnClickNext(){
	Debug.Log ("clicked");

	index += 1;
	var clip = clips [index];
	var clipPlayable = new AnimationClipPlayable(clip);
	clipPlayable.time = 0.0f;
	
	characterAnimator.Play (clipPlayable);
}

}

2

And how do we play that animation from layer index 1 instead of zero?