Animation won't play in all my prefabs

Hi, I'm trying to make several objects rotate, when I press the Vuforia Virtual button... I created a prefab, but only the one that is added to the inspector is the one that rotates... what can I do please?...

Code (CSharp):

1. using System;
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5. using Vuforia;
6.  
7. public class vbButton : MonoBehaviour, IVirtualButtonEventHandler {
8.  
9.     public GameObject vbBtnObj;
10.     public Animator cubeAni;
11.  
12. // Use this for initialization
13. void Start () {
14.         vbBtnObj = GameObject.Find("VirtualBtn");
15.         vbBtnObj.GetComponent<VirtualButtonBehaviour>().RegisterEventHandler(this);
16.         cubeAni.GetComponent<Animator>();
17. }
18.     public void OnButtonPressed(VirtualButtonBehaviour vb)
19.     {
20.         cubeAni.Play("cube_animation");
21.         Debug.Log("Button pressed");
22.     }
23.  
24.     public void OnButtonReleased(VirtualButtonBehaviour vb)
25.     {
26.         cubeAni.Play("none");
27.         Debug.Log("Button released");
28.     }
29. }