Object reference not set to an instance of an object - Jumping Scripts (C#)

I’m trying to jump and execute in another script when the player collides with an object using this code in a script that checks for a collision named “CheckCollisions”:

using UnityEngine;
using System.Collections;

public class CheckCollision : MonoBehaviour {
	private GameObject Player;
	private EndlessMode Jumpscripts;
	// Use this for initialization
	void Start () {
		Player = GameObject.Find ("Player");
	}
	 void OnCollisionEnter2D(Collision2D Player) {
		Debug.Log ("Collision Detected");
		Jumpscripts.StopGame ();
	}
}

The script its jumping to (“EndlessMode”) has this line of code that it should be executing:

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

public class EndlessMode : MonoBehaviour {

    	public void StopGame () {
    		HasPlayerDied = true;
    	}
}

But when the Player does collide with an obsticle, executing the CheckCollision “OnCollisionEnter2D” function, i get the following error:

“NullReferenceException: Object reference not set to an instance of an object
CheckCollision.OnCollisionEnter2D (UnityEngine.Collision2D Player) (at Assets/Scripts/CheckCollision.cs:20)”

You need to reference the EndlessMode script somewhere. You can do it in the Start function like this::

 using UnityEngine;
 using System.Collections;
 
 public class CheckCollision : MonoBehaviour {
     private GameObject Player;
     private EndlessMode Jumpscripts;
     // Use this for initialization
     void Start () {
         Jumpscripts = WHATEVERGAMEOBJECT.GetComponent<EndlessMode>();
         Player = GameObject.Find ("Player");
     }
      void OnCollisionEnter2D(Collision2D Player) {
         Debug.Log ("Collision Detected");
         Jumpscripts.StopGame ();
     }
 }