Why do I get a NullReferenceException

This is my Error: NullReferenceException: Object reference not set to an instance of an object PlayerJump.OnTouchDown () (at Assets/Scripts/PlayerJump.cs:17) UnityEngine.GameObject:SendMessage(String, Object, SendMessageOptions) TouchInput:Update() (at Assets/Scripts/TouchInput.cs:48)

I just can´t fix this error till weeks... I am trying to call a function of an another class "PlayerController":

'using UnityEngine; using System.Collections;

public class PlayerJump : MonoBehaviour {

 private PlayerController player;

 void awake()
 {
     player = gameObject.GetComponentInParent<PlayerController>();
 }

 void OnTouchDown()
 {
     
     Debug.Log("gedrueckt");
     player.playerJump();
 }

 void OnTouchStay()
 {
     Debug.Log("bleiben");
   
 }

 void OnTouchUp()
 {
     Debug.Log("loslassen");
 }

   

 

}'

everytime OnTouchDown gets calles the error occurs.... just can´t get why? I am doing the same thing from another class and it is working, I would be very thankful if somebody could tell me what´s wrong in this code :)