ARFoundation need help!

I just made simple application of placing object on plane but this error coming dont know why can any one help? i have attached the image.


here's my code :

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.ARFoundation;
using UnityEngine.Experimental.XR;
using System;

public class ARTapToPlaceObject : MonoBehaviour
{
public GameObject objectToPlace;
public GameObject placementIndicator;

private ARSessionOrigin arOrigin;
private Pose placementPose;
private bool placementPoseIsValid = false;

void Start()
{
arOrigin = FindObjectOfType<ARSessionOrigin>();
}

void Update()
{
UpdatePlacementPose();
UpdatePlacementIndicator();

if (placementPoseIsValid && Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
{
PlaceObject();
}
}

private void PlaceObject()
{
Instantiate(objectToPlace, placementPose.position, placementPose.rotation);
}

private void UpdatePlacementIndicator()
{
if (placementPoseIsValid)
{
placementIndicator.SetActive(true);
placementIndicator.transform.SetPositionAndRotation(placementPose.position, placementPose.rotation);
}
else
{
placementIndicator.SetActive(false);
}
}

private void UpdatePlacementPose()
{
var screenCenter = Camera.current.ViewportToScreenPoint(new Vector3(0.5f, 0.5f));
var hits = new List<ARRaycastHit>();
arOrigin.Raycast(screenCenter, hits, TrackableType.Planes);

placementPoseIsValid = hits.Count > 0;
if (placementPoseIsValid)
{
placementPose = hits[0].pose;

var cameraForward = Camera.current.transform.forward;
var cameraBearing = new Vector3(cameraForward.x, 0, cameraForward.z).normalized;
placementPose.rotation = Quaternion.LookRotation(cameraBearing);
}
}
}

 

hi
i think u forgot to drag prefab object for instantiate in unity hierarchy.

 

have you done?

 

try to add AR Raycast Manager to ARSessionOrigin & AR Camera Manager to MainCamera in ARFoundation 2.0