Solved NullReferenceExeption

The script InteractScriptFPSControler should set the FireFXFlameBall01 form the FireFXFlamBallScript to active by using SetActive to true.

public class InteractScriptFPSControler : MonoBehaviour
{
public float interactDistants = 5f;
bool keyActive119 = false;
GameObject FireFXFlameBall01 = null;

void Update ()
{
if (Input.GetKeyDown (KeyCode.O))
{
Ray ray = new Ray (transform.position, transform.forward);
RaycastHit hit;
if (Physics.Raycast (ray, out hit, interactDistants))
{
if (hit.collider.CompareTag ("Door119") && keyActive119 == true)
{
hit.collider.transform.GetComponent<Door119Script> ().ChangeDoorState ();
FireFXFlameBall01.SetActive (true);
}
}
}


public class FireFXFlameBall01 : MonoBehaviour
{
void Start ()
{
gameObject.SetActive (false);
}

The object is behind a door and smoke. Bij opening the door the FireFXFlameBall01 should get active, but I get an Error called:
NullReferenceException: Objectreference not set to an instance of an object.
The question is how can I fix this.

 

if(gameObject != null)
{
//do sth
}

or use try catch

 

Hi Jo,

When showing code in the forums please use Code Tags: http://forum.unity3d.com/threads/using-code-tags-properly.143875/

It looks like 'FireFXFlameBall01' is empty (it has no reference). So when you try to call SetActive on it, it'll say there's no object to call SetActive on.

Put the variable up like this

Code (CSharp):

1. public GameObject FireFXFlameBall01;

then attach the correct object to the script in the inspector (by dragging and dropping).

 

Thanks both Manlaikin and Nigey for your reply.

I'll tried this option first:
I changed the GameObject to public, yet I got a new Error wich is called as Unasigned Referance Exeption, this should be the problem that the object is empty.
How can I drag and drop the object into the script. The script is already assigned to the object (by using Add Component).
Do I need to do it like the video https://unity3d.com/learn/tutorials...between-components-gameobjects?playlist=17117 or can you tell me how.

 

you're not trying to add the script, but add something into the reference slot in the inspector for the script. Drag whatever you want the reference "FireFXFlameBall01" to refer to into the slot in the inspector

 

https://unity3d.com/learn/tutorials/modules/beginner/editor/the-inspector?playlist=17090

Take a look at this video here, and note how he's dragging objects from the scene into the variables in the Inspector. Find the GameObject with the script attached to it, that you need to reference, and drag it into the variable in the inspector, like in the video.