Object reference not set to an instance of an object (562380)

Hi
I have just updated my unity and have now started to run into some errors with my code. The main issue is :

NullReferenceException: Object reference not set to an instance of an object Player.Update () (at Assets/Scripts/Player.cs:48)

I have read online that it might be due to the highliter component not being declerd but I havent had this issue with my code before it was updated, I have also tryed declareing it and that isnt the issue. If someone could point me in the right direction it would be greatfully apreacated.

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.UI;
 
public class Player : MonoBehaviour {
 
    HighlighterComponent activeHighlighterComponent;
   
    [SerializeField]
    DisplayBoxInitializer boxInitializer;
 
    [SerializeField]
    GameObject recticle;
   
    int objectsSelected = 0;
 
    bool isActive = false;
 
    [SerializeField]
    Text text;
 
    // Use this for initialization
    void Start () {
 
        text.text = "Highlighting Active: " + isActive.ToString();
        Screen.lockCursor = true;
        recticle.SetActive(isActive);
 
    }
   
    // Update is called once per frame
    void Update () {
       
        Screen.lockCursor = true;
 
        if(isActive)
        {
 
            Ray ray;
 
            ray = new Ray(Camera.main.transform.position, Camera.main.transform.forward);
                Debug.DrawRay(Camera.main.transform.position, Camera.main.transform.forward, Color.green);
 
            RaycastHit hitInfo;
            if(Physics.Raycast(ray, out hitInfo ))
            {
                if(activeHighlighterComponent != null)
                {
                    HighlighterComponent inframeHighlightComponent = hitInfo.collider.GetComponent<HighlighterComponent>();
 
                    if(activeHighlighterComponent != inframeHighlightComponent)
                    {
                        boxInitializer.UnInitialize();
                        activeHighlighterComponent.RemoveHighlight();
                        activeHighlighterComponent = hitInfo.collider.GetComponent<HighlighterComponent>();
 
                        if(activeHighlighterComponent == null)
                        {
                            activeHighlighterComponent = hitInfo.collider.gameObject.AddComponent<HighlighterComponent>();
                        }
 
                        activeHighlighterComponent.AddHighlight();
                    }
                }
                else
                {
                    activeHighlighterComponent = hitInfo.collider.GetComponent<HighlighterComponent>();
                   
                    if(activeHighlighterComponent == null)
                    {
                        activeHighlighterComponent = hitInfo.collider.gameObject.AddComponent<HighlighterComponent>();
                    }
                   
                    activeHighlighterComponent.AddHighlight();
                }
 
 
 
                if((Input.GetMouseButtonUp(0) && !EventSystem.current.IsPointerOverGameObject()) || Input.GetButtonUp("Submit"))
                {
                    boxInitializer.Initialize(activeHighlighterComponent.gameObject);
                    objectsSelected++;
                }
            }
 
            if(Input.GetMouseButtonUp(1) || Input.GetButtonUp("Cancel"))
            {
                boxInitializer.UnInitialize();
            }
 
        }
 
        if(Input.GetButtonUp("Edit Highlighting"))
        {
            isActive = !isActive;
 
            if(!isActive)
            {
                boxInitializer.UnInitialize();
                activeHighlighterComponent.RemoveHighlight();
                activeHighlighterComponent = null;
 
            }
 
            text.text = "Highlighting Active: " + isActive.ToString();
 
            recticle.SetActive(isActive);
        }
    }
 
 
    void OnApplicationQuit()
    {
        //GoogleAnalytics.Client.SendEventHit("User Interaction", "Items Hit", "", objectsSelected);
        //GoogleAnalytics.Client.SendEventHit("User", "Play Time", "", (int)Time.realtimeSinceStartup);
    }
   
}

Add a break point at line 48 and 68. Then if it is null you can step through your else block and see if it gets assigned.