[Roll-a-ball] Changing UI text (NRE)

Hi, trying to follow roll-a-ball tutorial. Stuck at displaying score. This is the error I get:

 NullReferenceException: Object reference not set to an instance of an object
 PlayerController.SetScore () (at Assets/Scripts/PlayerController.cs:38)
 PlayerController.OnTriggerEnter (UnityEngine.Collider other) (at Assets/Scripts/PlayerController.cs:33)

This is my code:

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class PlayerController : MonoBehaviour {
 
     public Rigidbody rbody;
     public float speed ;
     private int score = 0;
     public Text scoreText;
 
     void Start ()
     {
         rbody = GetComponent<Rigidbody> ();
         scoreText = GetComponent<Text> ();
         SetScore ();
     }
 
     void FixedUpdate()
     {
         float moveHorizontal = Input.GetAxis ("Horizontal");
         float moveVertical = Input.GetAxis ("Vertical");
 
         Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);
 
         rbody.AddForce (movement * speed * Time.deltaTime);
     }
     void OnTriggerEnter(Collider other)
     {
         if (other.gameObject.tag == "pickup") {
             other.gameObject.SetActive(false);
             score++;
             SetScore();
         }
     }
     void SetScore()
     {
         scoreText.text = "Score: " + score;
     }
 }