Add RequireComponent attribute for required components on the

FadePlaneOnBoundaryChange component.

Assets/Scripts/UX/FadePlaneOnBoundaryChange.cs

 using UnityEngine;
 using UnityEngine.XR.ARFoundation;
 
+[RequireComponent(typeof(ARPlane))]
+[RequireComponent(typeof(Animator))]
 public class FadePlaneOnBoundaryChange : MonoBehaviour
 {
     const string k_FadeOffAnim = "FadeOff";