Open a door by standing on a button

I am very new to c# I know this is simple I just don't understand what the debugger is trying to tell me: using UnityEngine; using System.Collections;

public class Button : MonoBehaviour {

     public GameObject player;
     private int count;
     public GameObject door;

     // Use this for initialization
     void Start ()
     {

 
     }
 
     // Update is called once per frame
     void Update ()
     {
     if (count == 1) {
                     door.transform.position = new Vector3 (0, 50, 0);
 
             }
     }

     void OnTriggerEnter (Collider other)
     {
             if (other.gameObject == PlayerInits) {
                     count++;
             }
     }

     void OnTriggerExit (Collider other)
     {
             {
                     if (other.gameObject == player) {
                             count = Mathf.Max (0, count - 1);

                     }
             }
     }

}