OnMouseDown not work in Vuforia

I have a problem with Unity3D. I'm working on an AR project with Vuforia+Unity and I was testing the OnDownMouse() event so that when I play the GameObject and do an action, in this case just Debug.Log() to try.
But this only works the first time, and the second time I give play to try it doesn't work.
I've been looking at the colliders and they're well configured.
Another thing I noticed is that the script check disappears what I suspect may be the problem.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Click : MonoBehaviour
6. {
7.     void OnMouseDown()
8.     {
9.         Debug.Log("Hace CLICK!!!");
10.     }
11. }
12.  

 

Did you solve it and how?