Как реализовать систему смены спрайтов во время диалога

Здравствуйте такая вот проблемка. У меня есть массив с спрайтами и мне нужно перебирать и отображать спрайты в UI canvas вот код не понимаю че не работает Юнити вот так вот жалуется:

Массив:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

[CreateAssetMenu(menuName ="Dialogue/DialogueObject")]
public class DialogueObject : ScriptableObject
{
 [SerializeField] [TextArea] private string nameChar; 
 [SerializeField] private Sprite[] imgObj; 
 [SerializeField] [TextArea] private string[] dialogue;
 [SerializeField] private Response[] responses;

 public Sprite[] ImgObj => imgObj;
 public string NameChar => nameChar;

 public string[] Dialogue => dialogue;

 public bool HasResponses => Responses != null && Responses.Length > 0;

 public Response[] Responses => responses;
}

И вот сам код которым я пытаюсь отобразить изоображения:

 using UnityEngine;
using TMPro;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;



public class DialogueUI : MonoBehaviour
{
    [SerializeField] private GameObject dialogueBox;
    [SerializeField] private TMP_Text textLable;
    [SerializeField] private TMP_Text textName;
    [SerializeField] private Image imgHandler;

    public bool IsOpen {get; private set;}
    
    private ResponseHandler responseHandler;
    private TypeWriterEffect typeWriterEffect;
    private void Start() {
      typeWriterEffect=GetComponent<TypeWriterEffect>();
      responseHandler = GetComponent<ResponseHandler>();
      imgHandler = GetComponent<Image>();

      CloseDialogueBox();
      
    }

 

    public void ShowDialogue(DialogueObject dialogueObject){
        IsOpen = true;
        dialogueBox.SetActive(true);
        string nameChar = dialogueObject.NameChar;
        textName.text = nameChar;
        
        StartCoroutine(StepTroughtDialogue(dialogueObject));
        StartCoroutine (ImgInDialogue(dialogueObject));
    }

    public void AddResponseEvents(ResponseEvent[] responseEvents){
        responseHandler.AddResponseEvents(responseEvents);
    }



    private IEnumerator ImgInDialogue(DialogueObject dialogueObject){
        
        for (int i = 0; i < dialogueObject.ImgObj.Length; i++ ){
           Sprite imgObj = dialogueObject.ImgObj[i];

           imgHandler.sprite = imgObj;
            
           yield return null;
           yield return new WaitUntil(() => Input.GetKeyDown(KeyCode.Space));
        }
     
    }

    private IEnumerator StepTroughtDialogue(DialogueObject dialogueObject){

        for (int i = 0; i < dialogueObject.Dialogue.Length; i++ ){
            string dialogue = dialogueObject.Dialogue[i];
            
            

            yield return RunTypingEffect(dialogue);

            textLable.text = dialogue;
            
            
            if (i == dialogueObject.Dialogue.Length - 1 && dialogueObject.HasResponses) break;

            yield return null;
            yield return new WaitUntil(() => Input.GetKeyDown(KeyCode.Space));

        }

        if (dialogueObject.HasResponses)
        {
            responseHandler.ShowResponses(dialogueObject.Responses);
        } 
        else 
        {
            CloseDialogueBox();
        }

        
    } 

    private IEnumerator RunTypingEffect(string dialogue){
        typeWriterEffect.Run(dialogue, textLable);

        while (typeWriterEffect.IsRunning){
            yield return null;

            if (Input.GetKeyDown(KeyCode.Space)){
                typeWriterEffect.Stop();
            }
        }
    }



    public void CloseDialogueBox(){
        IsOpen = false;
        dialogueBox.SetActive(false);
        textName.text=string.Empty;
        textLable.text=string.Empty;
        
    }


}