Bug NullReferenceException: Object reference not set to an instance of an object

I'm making a game and I'm currently working on the message to show that the player won when their score gets high enough, but for some reason I'm getting an error and the message isn't showing up. I've been stuck on this for like a week and I'm not sure how to solve this.

The error I'm getting is:

NullReferenceException: Object reference not set to an instance of an object

PlayerController.SetCountText () (at Assets/Scripts 1/PlayerController.cs:48)



I'm almost certain it is because I am refernceing a game object in one script from another one but I don't know exactly what the issue is or how to solve it.

The first script is PlayerController script where the error is coming from and the second is where the winTextObject is.



Here is the first:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.InputSystem;
5. using TMPro;
6. using UnityEngine.SceneManagement;
7.  
8. public class PlayerController : MonoBehaviour
9. {
10.     public float speed = 0;
11.     public TextMeshProUGUI countText;
12.     public Timer timer;
13.  
14.     private Rigidbody rb;
15.     public int count;
16.     private float movementX;
17.     private float movementY;
18.  
19.    
20.      // Start is called before the first frame update
21.     void Start()
22.     {
23.         rb = GetComponent<Rigidbody>();
24.         count = 0;
25.  
26.         SetCountText();
27.        
28.         timer.winTextObject.SetActive(false);      
29.     }
30.  
31.     void OnMove(InputValue movementValue)
32.     {
33.        Vector2 movementVector = movementValue.Get<Vector2>();
34.  
35.        movementX = movementVector.x;
36.        movementY = movementVector.y;
37.     }
38.  
39.     void SetCountText()
40.     {
41.         countText.text = "Count: " + count.ToString();
42.        
43.        
44.        
45.         if(count == 40)
46.         {
47.             timer.winTextObject.SetActive(true);
48.         }
49.     }
50.  
51.     void FixedUpdate()
52.     {
53.         Vector3 movement = new Vector3(movementX, 0.0f, movementY);
54.  
55.         rb.AddForce(movement * speed);
56.  
57.        
58.     }
59.  
60.     private void OnTriggerEnter(Collider other)
61.     {
62.         if(other.gameObject.CompareTag("PickUp"))
63.         {
64.             other.gameObject.SetActive(false);
65.             count = count + 1;
66.  
67.             SetCountText();
68.         }
69.  
70.        
71.         if (count == 10)
72.         {
73.             if (other.tag == "LevelExit")
74.             {
75.                 SceneManager.LoadScene(1);
76.             }
77.         }
78.  
79.         if (count == 40)
80.         {
81.             if (other.tag == "LevelExit")
82.             {
83.                 SceneManager.LoadScene(2);
84.             }
85.         }
86.     }
87. }
88.  

And the Second:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using TMPro;
5.  
6. public class Timer : MonoBehaviour
7. {
8.     public PlayerController playerController;
9.    
10.     public GameObject loseTextObject;
11.     public GameObject winTextObject;
12.    
13.     [Header("Component")]
14.     public TextMeshProUGUI timerText;
15.  
16.     [Header("Timer Settings")]
17.     public float currentTime;
18.     public bool countDown;
19.  
20.     [Header("Limit Settings")]
21.     public bool hasLimit;
22.     public float timerLimit;
23.  
24.     [Header("Format Settings")]
25.     public bool hasFormat;
26.     public TimerFormats format;
27.     private Dictionary<TimerFormats, string> timeFormats = new Dictionary<TimerFormats, string>();
28.  
29.     // Start is called before the first frame update
30.     void Start()
31.     {
32.         timeFormats.Add(TimerFormats.Whole, "0");
33.         timeFormats.Add(TimerFormats.TenthDecimal, "0.0");
34.         timeFormats.Add(TimerFormats.HundrethsDecimal, "0.00");
35.         timeFormats.Add(TimerFormats.ThousanthsDecimal, "0.000");
36.  
37.         loseTextObject.SetActive(false);
38.     }
39.  
40.     // Update is called once per frame
41.     void Update()
42.     {
43.         currentTime = countDown ? currentTime -= Time.deltaTime : currentTime += Time.deltaTime;
44.  
45.         if(hasLimit && ((countDown && currentTime <= timerLimit) || (!countDown && currentTime >= timerLimit)))
46.         {
47.             currentTime = timerLimit;
48.             SetTimerText();
49.             timerText.color = Color.red;
50.             enabled = false;
51.         }
52.  
53.         if(timerText.Equals("0.00") && playerController.count < 40)
54.         {
55.             loseTextObject.SetActive(true);
56.         }
57.  
58.         SetTimerText();
59.     }
60.  
61.     private void SetTimerText()
62.     {
63.         timerText.text = hasFormat ? currentTime.ToString(timeFormats[format]) : currentTime.ToString();
64.     }
65. }
66.  
67. public enum TimerFormats
68. {
69.     Whole,
70.     TenthDecimal,
71.     HundrethsDecimal,
72.     ThousanthsDecimal
73. }
74.  

 

The error doesnt lie
Look at the line, workout whats null
fix it.

it is no more hard than that

 

It is difficult when the error points to the end of a method:

Code (CSharp):

1. if(count == 40)
2.         {
3.             timer.winTextObject.SetActive(true);
4.         } //<--- compile error

So you have to look into that method and see where it can mess up, or debug by doing something like this:

Code (CSharp):

1. if(count == 40)
2. {
3.     if (timer.winTextObject == null)
4.     {
5.         print("timer winTextObject does not exist right now!!!");
6.     }
7.     else
8.     {
9.         timer.winTextObject.SetActive(true);
10.     }
11. }

So... like Kurt says, "When in doubt, print it out!".

 

Yoop... thanks Wide!

The answer is always the same... ALWAYS!

How to fix a NullReferenceException error

https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/

Three steps to success:
- Identify what is null <-- any other action taken before this step is WASTED TIME
- Identify why it is null
- Fix that