how to activate a object with button?

So I use a button assest for android an so my button looks like this and I want to activate a object thats deactivated with "gameObject.SetActive (false);.

using UnityEngine;
using System.Collections;

public class spawnParachute : MonoBehaviour {

    //cube I want to spawn
public GameObject Cube;

//button to use for going to the game
public EasyButton parachute;


//this is the buttons name after "string"
void On_ButtonUp (string parachute)
{
	// thats the button and string
	if (parachute == "parachute")
	{
                    //This is the only part worth looking at
		GameObject.Find("Cube").SetActive (true);
	}
}

}

I get the error “object refrence not set to instance of object”

GameObject.Find will only retrieve objects that are enabled.

You can find this information in the unity scripting reference:

“This function only returns active gameobjects.”

What you will want to do is keep a reference to the object before you disable it. Then use that reference to re-enable it.

The code would look something like this:

public class Temp : MonoBehaviour
{
    private GameObject m_cube;

	// Use this for initialization
	void Start ()
    {
        m_cube = GameObject.Find("Cube");
        m_cube.SetActiveRecursively(false);
	}

    void EnableObject()
    {
        m_cube.SetActiveRecursively(true);
    }
}