How to use a list to populate a target object?

The intended behavior is that the GroundRoom object should pass a list of objects of interest to the director script. The director script then instructs the controller script to move the gameobject to the target (in this case the first object in the list).

However, I keep getting null reference exceptions. Is this because the object is never properly added to the list? How do I fix this?

Thank you in advance for your help.
(Edit: updated code and included runtime errors below.)

ObjectOfInterest.cs

using UnityEngine;
using System.Collections.Generic;

public class ObjectOfInterest : MonoBehaviour {
	
	public string objectName;
	private Room room;
	
	// Use this for initialization
	void Start () {
	room = gameObject.GetComponent<Room>();
	room.objectsInRoom.Add(gameObject);
	}
	
	// Update is called once per frame
	void Update () {
	
	}
}

Room.cs

using UnityEngine;
using System.Collections.Generic;

public class Room : MonoBehaviour {
	
	public List<GameObject> objectsInRoom = new List<GameObject>();
	
	// Use this for initialization
	void Start () {

	}
	
	// Update is called once per frame
	void Update () {
	
	}
}

Director.cs

using UnityEngine;
using System.Collections;

public class Director : MonoBehaviour {
	
	private GameObject target;
	private Controller controller;
	private GameObject roomObject;
	private Room roomScript;
	
	// Use this for initialization
	void Start () {
	controller = gameObject.GetComponent<Controller>();
	roomObject = GameObject.Find ("GroundRoom");
	roomScript = roomObject.GetComponent<Room>();
	}
	
	// Update is called once per frame
	void Update () {
	target = roomScript.objectsInRoom[0];	
	}
	
	public GameObject Target () {
		return target;
	}
	
	
}

Controller.cs

using System.Collections;

public class Controller : MonoBehaviour {
	
	private Director director;
	public float speed;
	public float rotationSpeed;
	Vector3 direction = new Vector3();
	Vector3 targetLocation = new Vector3();
	Quaternion looking = new Quaternion();
	public enum state {moving, idle};
	public static state MyState;
	private GameObject target;
		
	// Use this for initialization
	void Start () {
	director = gameObject.GetComponent<Director>();
	//set default speed and rotationSpeed;
	if (speed == 0) {
		speed = 100;
		}
	if (rotationSpeed == 0) {
		rotationSpeed = 100;
		}
	}
	
	// Update is called once per frame
	void Update () {
		target = director.Target();
		MoveTo ();
		RotateTo ();
	}
	
	void MoveTo () {
		targetLocation = target.transform.position;
		targetLocation.y = transform.position.y;
		transform.position = Vector3.MoveTowards(transform.position, targetLocation, speed * Time.deltaTime);
	}
	
	void RotateTo () {
		targetLocation = target.transform.position;
		direction = (targetLocation - transform.position).normalized;
		looking = Quaternion.LookRotation(direction);
		looking.x = 0;
		looking.z = 0;
		transform.rotation = Quaternion.Slerp(transform.rotation, looking, Time.deltaTime * rotationSpeed);
	}
}

The Exceptions at runtime are:

Not getting ArgumentOutOfRangeException ever since I initialized the list.

NullReferenceException at targetLocation = target.transform.position; in the Controller script, MoveTo() function, line 36.

The null reference exception is because you never initialize your list. Line 26 should be:

 public List<GameObject> objectsInRoom = new List<GameObject>();

Also depending on how you are using this list, you may want it to be a list of ObjectOfInterest rather than GameObject.

Just solved it by talking myself through the scripts.
My list objectsInRoom was being initialized after ObjectOfInterest.cs tried to add a gameobject to it. Order of operations error.

Thanks for your help folks!