Unity 4.6 UI Slider NullReferenceException

I’m trying to migrate from NGUI to the new native UI system, I’m getting a strange NullReferenceException in my slider…

First of all, I use my slider as a healthbar, so I’ve deleted the handle object and disabled “interactable”.

I’ve attached a script to the slider object, this script

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class HealthScript : MonoBehaviour {

public static bool eatNow;

// public GameObject pHealthBar;
Slider healthSlider;

float health;

// float healthValue;

void Start(){
	health = 100f;
	eatNow = false;
	healthSlider = GetComponent<Slider>();

// healthValue = healthSlider.value;
}

void Update(){

// health = health - 0.05f;
healthSlider.value = health;
health = health - 0.05f;
Debug.Log (health);

	if (eatNow == true){
		eatNow = false;
		HealthRise();
	}
}

I get an exception in a line in the update

healthSlider.value = health;

I’ve tried declaring healthSlider as public, but it still throws the exception…

What’s wrong with my code? I’ve managed to resolve nullreferenceexceptions errors in the past, I’m stuck with this one…

The line where you get the Slider component is probably returning null, make sure the game object with the HealthScript component attached also has the Slider component attached.