NullReferenceException[C#][FIXED]

Questions & Answers
1

Hello fellow unity devs, i was coding away at a kind of spawning system but it just doesn’t work, and i can’t figure out why. It throws a NullReferenceException whenever i call SpawnStump().

Actual error: NullReferenceException
UnityEngine.Component.get_transform () (at C:/BuildAgent/work/d3d49558e4d408f4/artifacts/EditorGenerated/UnityEngineComponent.cs:19)
GameHandler.SpawnStump () (at Assets/Code/GameHandler.cs:31)
GameHandler.Update () (at Assets/Code/GameHandler.cs:20)

public Transform startStump;
    public GameObject stumpToSpawn;
    public float spawnPosYDiff = 1;
    Transform spawnPosTransform;

	// Use this for initialization
	void Start () {
    startStump = GameObject.Find("Stump1").transform;
	}
	
	// Update is called once per frame
	void Update () {
        if (Input.GetButtonDown("SpawnStump")) {
            Debug.Log("LOG");
            SpawnStump();
        }
	}

    void SpawnStump() {
        Vector3 SpawnPos;
        SpawnPos.x = startStump.position.x;
        SpawnPos.y = startStump.position.y + spawnPosYDiff;
        SpawnPos.z = startStump.position.z;
        spawnPosYDiff += 1;

        spawnPosTransform.transform.position = SpawnPos;

        
        
        stumpToSpawn = Instantiate(stumpToSpawn, spawnPosTransform.transform.position, startStump.transform.rotation) as GameObject;
        
    }

Does anybody know what is going wrong?

EDIT: Figured it out. Turned out spawnPosTransform was empty, so i just took the transform of an empty gameobject and used that. Next to that i moved the code from the Start void to the Awake void. All is fine now!

3

Looks like your spawnPosTransform field is null.

Try to avoid using GameObject.Find(). It’s slow and generally means you can improve your architecture.

2

You dont create a new Vector3 you just use it:

instead of line 20-23 write this:

Vector3 SpawnPos = new Vector3(startStump.position.x,startStump.position.y + spawnPosYDiff,startStump.position.z);