Missing Reference Exception

I'm new to Unity and to coding. I've tried a number of solutions to correct the Missing Reference Exception. I have not been able to find a solution. I've attached the script below. I'm using boulders as hazards that the player must avoid in this game I'm building. When the player's raft hits the boulder in the river the raft flips. I welcome any help anyone can offer to correct this error.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;


public class simpleCollision : MonoBehaviour {
public GameObject raft;
public GameObject raft1Prefab;
public Transform raftbracket;
public Text messageText;
public Text gameOverText;


private bool gameOver;
private bool restart;



void Start ()
{
restart = false;
messageText.text = "";
gameOver = false;

}
void Update ()
{

if(raft == null)
{
raft = GameObject.FindWithTag ("Raft");
}
if (restart) {
if (Input.GetKeyDown (KeyCode.R)) {
SceneManager.LoadScene (SceneManager.GetActiveScene ().buildIndex);
}
}
}
// Use this for initialization
void OnTriggerEnter(Collider other)
{
if(other.CompareTag ("Raft"))
Instantiate (raft1Prefab, raftbracket.transform.position, raftbracket.transform.rotation);
Destroy (other.gameObject);

gameOverText.text = "Game Over!";
gameOver = true;
messageText.text = "Press 'R' to restart";
restart = true;

}

}

 

I've supplied my script with tags and a screen shot of the error message from the console. Any coaching you can provide will be appreciated. I'm very new and teaching myself. thanks

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;


public class simpleCollision : MonoBehaviour {
public GameObject raft;
public GameObject raft1Prefab;
public Transform raftbracket;
public Text messageText;
public Text gameOverText;
private bool gameOver;
private bool restart;

// re-establilshing opening conditions
void Start ()
{
restart = false;
messageText.text = "";
gameOver = false;
}
void Update ()
{
//make raft null to acknowledge the raft has been destoyed
if(raft == null)
{
raft = GameObject.FindWithTag ("Raft");
}
// restarting the game
if (restart) {
if (Input.GetKeyDown (KeyCode.R)) {
SceneManager.LoadScene (SceneManager.GetActiveScene ().buildIndex);
}
}
}
// setting up collision results: switching raft for raft1prefab, destroying raft telling player game over and restart
void OnTriggerEnter(Collider other)
{

Instantiate (raft1Prefab, raftbracket.transform.position, raftbracket.transform.rotation);
Destroy (other.gameObject);
gameOverText.text = "Game Over!";
gameOver = true;
messageText.text = "Press 'R' to restart";
restart = true;
}

}

 

This is what is meant by code tags:
https://forum.unity.com/threads/using-code-tags-properly.143875/

Also, the error you have shown occurs in FollowTarget.cs on line 19, but you've posted a completely different script.

 

Thanks for noticing that ! I've attached the FollowTarget script. I just never thought my camera script would be the issue.

Any coaching will be appreciated.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FollowTarget : MonoBehaviour {

public GameObject player;
public Vector3 offset;

void Start ()
{

offset = transform.position - player.transform.position;
}


void LateUpdate ()
{
transform.position = player.transform.position + offset;

}
}

 

Please post code using "code" tags as in the link I included. You're making it unnecessarily difficult to find line 19 of your script by not doing so. And if the line numbers shift, please say which line is the original line 19.

 

Sorry for the missing tags.

I've attached a new copy of the script with line numbers.

1. using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FollowTarget : MonoBehaviour {

public GameObject player;
public Vector3 offset;
// wanting the main camera to follow the player raft
// establishing camera position
11. void Start ()
{

offset = transform.position - player.transform.position;
}

//updating camera positioin
void LateUpdate ()
19. {
transform.position = player.transform.position + offset;

}
}

 

Code (CSharp):

1. public string ThisIsACodeTag;

The problem though, is your 'player' GameObject is null. I'm assuming you meant to set it in the inspector, but it is an empty (missing) reference.

An ugly fix

If you take the player GameObject in the hierarchy, and add a tag of Player, you could do this instead

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class FollowTarget : MonoBehaviour {
6.  
7.   public GameObject player;
8.   public Vector3 offset;
9.  
10.   void Start ()
11.   {
12.     if (player==null) {
13.       player = GameObject.FindWithTag("Player");
14.     }
15.     offset = transform.position - player.transform.position;
16.   }
17.  
18.   void LateUpdate ()
19.   {
20.     transform.position = player.transform.position + offset;
21.   }
22. }
23.  

 

Lloyd,

I appreciate your time and help. I'll give it a shot and let you know.

Thanks

William

 

Lloyd,

I've made the changes you suggested bu there is no change in the error message except it is now line 22.( which is line 3 below). Is there another way I could have the main camera follow the player?

1. void LateUpdate ()
2. {
3. transform.position = player.transform.position + offset;
4. }

 

Did you assign your player object the "Player" tag? If so, does the player object exist at the time Start in FollowTarget is run?

Also, can you please just click the link I put in comment #4 and follow the instructions for using "code" tags when posting code?

 

Joe,

Thanks fo the link. I got it.

object is assigned with tag "Player". No it does not exist at the time Start in FollowTarget is run.

Question, the error does not appear in the console until after Player collides and is destroyed. Could Player be null during the LateUpdate in FollowTarget and causing the error notice? If so would I need to reestablish Player at the beginning of LateUpdate?

Thanks

 

If player is going to be null for just a few frames, I would just do this and not worry about it, unless you really need to move transform.position every single frame.

Code (csharp):

1. void LateUpdate ()
2. {
3.     if (player != null)
4.     {
5.         transform.position = player.transform.position + offset;
6.     }
7. }

 

Joe,

Your suggestion makes a lot of sense. I'll give it a try and let you know. In the mean time, thanks for your time and suggestions.

All the best,

William

 

Joe,

You're great! It worked like a charm!