Object reference not set to an instance of an object Camera.main.ScreenPointToRay (Input.mousePosition)

Questions & Answers
1

This has been asked before, I have seen it, but none of those answers could help me.

With the code below I get the following error:
Object reference not set to an instance of an object (line 9)
The error is on var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
When I debug Input.mousePosition the Z is always 0.0. Is that the problem?
Or how do I fix it?

#pragma strict

var speed : float = 20.0;
var move : boolean;
var wantedPosition : Vector3;

function Update () {
if ( Input.GetMouseButtonDown ( 0 ) ) {
    var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
    var hit : RaycastHit;
   
    if ( Physics.Raycast (ray, hit) ) {
        move = true;
        wantedPosition = hit.point + Vector3 ( 0.0, 30.0, 0.0 );
    }
}

if ( move ) {
    transform.LookAt ( wantedPosition );
    transform.Translate ( Vector3.forward *  Time.deltaTime * speed );
   
    if ( Vector3.Distance ( transform.position, wantedPosition ) < 0.01 ) {
        move = false;
    }
}
}

Did I do something wrong? I just followed a tutorial.

2

This problem is likely because you’ve changed the tag on your camera. The use of ‘Camera.main’ depends on the camera having the tag ‘MainCamera’.