Getting error "NullReferenceException: Object reference not set to an instance of an object"

Full error:
NullReferenceException: Object reference not set to an instance of an object
Collisions.OnCollisionEnter (UnityEngine.Collision other) (at Assets/Scripts/Collisions.cs:23)

My Collisions script:

using UnityEngine;
using System.Collections;

[RequireComponent(typeof(EnemyPatrol))]

public class Collisions : MonoBehaviour
{
public Transform spawnPoint;
public int deaths;
public EnemyPatrol enemyPatrol;

void Start()
{
	enemyPatrol = GetComponent<EnemyPatrol>();
}

void OnCollisionEnter(Collision other)
{
	if(other.transform.tag == "Enemy")
	{
		transform.position = spawnPoint.position;
		deaths = deaths + 1;
		enemyPatrol.Reset();
	}
}

}

My EnemyPatrol script:

using UnityEngine;
using System.Collections;

public class EnemyPatrol :MonoBehaviour
{
public Transform patrolPoints;
public float moveSpeed;
private int currentPoint;

void Start()
{
	transform.position = patrolPoints[0].position;
	currentPoint = 0;
}

void Update()
{
	if(transform.position == patrolPoints[currentPoint].position)
	{
		currentPoint++;
	}

	if(currentPoint == patrolPoints.Length)
	{
		currentPoint = 0;
	}

	transform.position = Vector3.MoveTowards(transform.position, patrolPoints[currentPoint].position, moveSpeed * Time.deltaTime);
}

public void Reset()
{
	transform.position = patrolPoints[0].position;
}

}

Please learn to format code.