What's wrong?

Unity is indicating this error when starting the game:

ArgumentException: Index out of bounds.
ControllerTree2.Update () (at Assets/Scripts/ControllerTree2.cs:14)

using UnityEngine;
using System.Collections;

public class ControllerTree2 : MonoBehaviour {
Animator TrunkAnimator;
// Use this for initialization
void Start () {
TrunkAnimator = GetComponent ();

// Update is called once per frame
void Update () {

	Touch touch = Input.GetTouch(0);
	if(touch.phase == TouchPhase.Began){
		if(touch.position.x > Screen.width/2){
			TrunkAnimator.SetBool ("Attack2", true);
			TrunkAnimator.SetBool ("Stop2", false);
		} else {
			TrunkAnimator.SetBool ("Attack2", false);
			TrunkAnimator.SetBool ("Stop2", true);


If you’re not touching the screen, Input.GetTouch(0); will fail because there isn’t a touch to get. You should check the lengt of Input.touches first.