Not sure what this error is telling/asking me to do?

I watched a video on an interaction script (because I suck at scripting), and I did all according to plan. However, I get t$$anonymous$$s error message "NullReferenceException: Object reference not set to an instance of an object Interact.Update() (at Assets/Interact.cs:50)" and i have no idea what it is telling me to do in order to fix it.

My code: using UnityEngine; using System.Collections; using UnityEngine.UI;

 public class Interact : MonoBehaviour
 {
     public string interactButton;
 
     public float InteractDistance = 3f;
     public LayerMask interactLayer; //filter
 
     public Image interactIcon; //Picture to show if you can interact or not
 
     public bool isInteracting;
 
     // Use t$$anonymous$$s for initialization
     void Start ()
     {
         //set interact icon to be invisible
         if(interactIcon != null)
         {
             interactIcon.enabled = false;
         }
     }
     
     // Update is called once per frame
     void Update ()
     {
         Ray ray = new Ray(transform.position, transform.forward);
         RaycastHit $$anonymous$$t;
 
         //Shoots a ray
         if(Physics.Raycast(ray, out $$anonymous$$t, InteractDistance, interactLayer))
         {
             //Checks if we are not interacting
             if (isInteracting == false)
             {
                 if(interactIcon != null)
                 {
                     interactIcon.enabled = true;
                 }
 
                 //If we press the interaction button
                 if (Input.GetButtonDown("Interact"))
                 {
                     //If it is a Door
                     if ($$anonymous$$t.collider.CompareTag("Door"))
                     {
                         //Open or Close it
                         $$anonymous$$t.collider.GetComponent<Door>().ChangeDoorState();
                     }
                 }
             }
         }
     }
 }

Line 50 = $$anonymous$$t.collider.GetComponent().ChangeDoorState();

I thought it was telling me to name the gameobject "Door" but i guess thats not the issue :( Thanks!