EnemyAI C# Error

Hi! I've just got an Small error and i don't know why :/ I Get A NullReferenceException error in Line 33 And i don't know :/

Here's the Script:

using UnityEngine; using System.Collections;

public class EnemyAI : MonoBehaviour { public int minRange; public bool follow; public float moveSpeed; public float rotationSpeed; private Transform myTransform; private Transform player;

 void Start()
 {
     myTransform = transform;
     player = GameObject.FindGameObjectWithTag("Player").transform;
 }

 void Update ()
 {
     if(player != null && Vector3.Distance(player.position, myTransform.position) < minRange)
     {
         follow=true;
     }

     if(follow && player != null)
     {
         myTransform.rotation = Quaternion.Slerp(myTransform.rotation, Quaternion.LookRotation(player.position - myTransform.position), rotationSpeed * Time.deltaTime);
         myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;
     }

if(player == null) { GameObject.FindGameObjectWithTag("Player").transform; } } }

Any Ideas to fix it :)?

This is the Problem:

If(player == null){ GameObject.FindGameObjectWithTag("Player").transform; }