QuestSystemSaveTest 수강 후 오류

안녕하세요 선생님

강의를 열심히 따라 듣고있던 중 세이브 & 로드 구현하고 테스트하는 와중 에러메세지 때문에 몇일 고민하다가 도저히 안되겠어서 글 남깁니다

어딘가 오타가있는건 아닌지 꼼꼼히 확인해봤는데 제눈엔 도저히 찾질 못하겠습니다 ㅜㅜ

우선 에러메세지는 다음과 같습니다

세이브 테스트 오브젝트에 스크립트도 잘 부착하였구요

스크립터블 오브젝트도 강의와 똑같이 만들고 부착하였습니다

어느 스크립트가 문제인지 몰라 Quest, QuestSystem, QuestSystemSaveTest

세가지 스크립트 작성하여 등록하겠습니다

Quest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Linq;
using System.Diagnostics;

using Debug = UnityEngine.Debug;

public enum QuestState
{
    Inactive,
    Running,
    Complete,
    Cancel,
    WaitingForCompletion // 퀘스트 완료시 자동으로 완료되는게 아닌, 사용자가 퀘스트 완료를 눌러야 완료되는 상태
}

[CreateAssetMenu(menuName = "Quest/Quest", fileName ="Quest_")]
public class Quest : ScriptableObject
{

    #region Event
    public delegate void TaskSuccessChangeHandler(Quest quest, Task task, int currentSuccess, int prevSuccess);
    public delegate void CompleteHandler(Quest quest);
    public delegate void CancelHandler(Quest quest);
    public delegate void NewTaskGroupHandler(Quest quest, TaskGroup currentTaskGroup, TaskGroup prevTaskGroup);
    #endregion


    [SerializeField]
    private Category category;
    [SerializeField]
    private Sprite icon;

    [Header("Text")]
    [SerializeField]
    private string codeName;
    [SerializeField]
    private string displayName;
    [SerializeField, TextArea]
    private string description;

    [Header("Task")]
    [SerializeField]
    private TaskGroup[] taskGroups;

    [Header("Reward")]
    [SerializeField]
    private Reward[] rewards;

    [Header("Condition")]
    [SerializeField]
    private Condition[] acceptionConditions;
    [SerializeField]
    private Condition[] cancelConditions;

    [Header("Option")]
    [SerializeField]
    private bool useAutoComplete;
    [SerializeField]
    private bool isCancelable; // 캔슬 불가능한 퀘스트를 위한 변수
    [SerializeField]
    private bool isSaveable;

    private int currentTaskGroupIndex;

    #region 프로퍼티들
    public Category Category => category;
    public Sprite Icon => icon;
    public string CodeName => codeName;
    public string DisplayName => displayName;
    public string Description => description;
    public QuestState State { get; private set; }
    public TaskGroup CurrentTaskGroup => taskGroups[currentTaskGroupIndex];
    public IReadOnlyList<TaskGroup> TaskGroups => taskGroups;
    public IReadOnlyList<Reward> Rewards => rewards;
    public bool IsRegistered => State != QuestState.Inactive;
    public bool IsCompletable => State == QuestState.WaitingForCompletion;
    public bool IsComplete => State == QuestState.Complete;
    public bool IsCancel => State == QuestState.Cancel;
    public virtual bool IsCancelable => isCancelable && cancelConditions.All(x=>x.IsPass(this));
    public bool IsAcceptable => acceptionConditions.All(x => x.IsPass(this));
    public virtual bool IsSaveable => isSaveable;
    #endregion

    public event TaskSuccessChangeHandler onTaskSuccessChanged;
    public event CompleteHandler onCompleted;
    public event CancelHandler onCanceled;
    public event NewTaskGroupHandler onNewTaskGroup;

    // Awake 역할의 함수로 Quest가 System에 등록되면 실행될 함수
    public void OnRegister()
    {
        // 퀘스트를 중복 등록했을경우 에러 발생
        Debug.Assert(!IsRegistered, "This quest has already been registered.");

        foreach (var taskGroup in taskGroups)
        {
            taskGroup.Setup(this);
            foreach (var task in taskGroup.Tasks)
                task.onSuccessChanged += OnSuccessChanged;
        }

        State = QuestState.Running;
        CurrentTaskGroup.Start();
    }

    public void ReceiveReport(string category, object target, int successCount)
    {
        Debug.Assert(IsRegistered, "This quest has already been registered.");
        Debug.Assert(!IsCancel, "this quest has been canceled");

        if (IsComplete)
            return;

        CurrentTaskGroup.ReceiveReport(category, target, successCount);

        if (CurrentTaskGroup.IsAllTaskComplete)
        {
            if (currentTaskGroupIndex + 1 == taskGroups.Length) // 다음 taskGroup이 없다면
            {
                State = QuestState.WaitingForCompletion;
                if (useAutoComplete)
                    Complete();
            }
            else
            {
                var prevTaskGroup = taskGroups[currentTaskGroupIndex++];
                prevTaskGroup.End();
                CurrentTaskGroup.Start();
                onNewTaskGroup?.Invoke(this, CurrentTaskGroup, prevTaskGroup);
            }
        }
        else
            State = QuestState.Running;
    }

    public void Complete()
    {
        CheckIsRunning();

        foreach (var taskGroup in taskGroups)
            taskGroup.Complete();

        State = QuestState.Complete;

        foreach (var reward in rewards)
        {
            reward.Give(this);
        }

        onCompleted?.Invoke(this);

        onTaskSuccessChanged = null;
        onCompleted = null;
        onCanceled = null;
        onNewTaskGroup = null;
    }

    public virtual void Cancel()
    {
        CheckIsRunning();
        Debug.Assert(IsCancelable, "this quest can't be canceled");

        State = QuestState.Cancel;
        onCanceled?.Invoke(this);
    }

    public Quest Clone()
    {
        var clone = Instantiate(this);
        clone.taskGroups = taskGroups.Select(x => new TaskGroup(x)).ToArray();
        return clone;
    }

    public QuestSaveData ToSaveData()
    {
        return new QuestSaveData
        {
            codeName = codeName,
            state = State,
            taskGroupIndex = currentTaskGroupIndex,
            taskSuccessCounts = CurrentTaskGroup.Tasks.Select(x => x.CurrentSuccess).ToArray()
        };
    }

    public void LoadFrom(QuestSaveData saveData)
    {
        State = saveData.state;
        currentTaskGroupIndex = saveData.taskGroupIndex;

        for (int i = 0; i < currentTaskGroupIndex; i++)
        {
            var taskGroup = taskGroups[i];
            taskGroup.Start();
            taskGroup.Complete();
        }

        for (int i = 0; i < saveData.taskSuccessCounts.Length; i++)
        {
            CurrentTaskGroup.Start();
            CurrentTaskGroup.Tasks[i].CurrentSuccess = saveData.taskSuccessCounts[i];
        }
    }

    private void OnSuccessChanged(Task task, int currentSuccess, int prevSuccess)
        => onTaskSuccessChanged?.Invoke(this, task, currentSuccess, prevSuccess);


    [Conditional("UNITY_EDITOR")] // 유니티 에디터로 시행할때만 작동하도록 함
    private void CheckIsRunning()
    {
        Debug.Assert(IsRegistered, "This quest has already been registered.");
        Debug.Assert(!IsCancel, "this quest has been canceled");
        Debug.Assert(!IsComplete, "this quest has already been completed");
    }

}

QuestSystem.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Linq;
using Newtonsoft.Json.Linq;

public class QuestSystem : MonoBehaviour
{
    #region Save Path
    private const string kSaveRootPath = "questSystem";
    private const string kActiveQuestsSavePath = "activeQuests";
    private const string kCompletedQuestsSavePath = "completedQuests";
    private const string kActiveAchievementsSavePath = "activeAchievements";
    private const string kCompletedAchievementsSavePath = "completedAchievements";
    #endregion

    #region Events
    public delegate void QuestRegisteredHandler(Quest newQuest);
    public delegate void QuestCompletedHandler(Quest quest);
    public delegate void QuestCanceledHandler(Quest quest);
    #endregion

    private static QuestSystem instance;
    private static bool isApplicationQuitting;

    public static QuestSystem Instance
    {
        get
        {
            if(!isApplicationQuitting && instance == null)
            {
                instance = FindObjectOfType<QuestSystem>();
                if(instance == null)
                {
                    instance = new GameObject("Quest System").AddComponent<QuestSystem>();
                    DontDestroyOnLoad(instance.gameObject);
                }
            }
            return instance;
        }
    }

    private List<Quest> activeQuests = new List<Quest>();
    private List<Quest> completedQuests = new List<Quest>();

    private List<Quest> activeAchievements = new List<Quest>();
    private List<Quest> completedAchievements = new List<Quest>();

    private QuestDatabase questDatabase;
    private QuestDatabase achievementDatabase;

    public event QuestRegisteredHandler onQuestRegistered;
    public event QuestCompletedHandler onQuestCompleted;
    public event QuestCanceledHandler onQuestCanceled;

    public event QuestRegisteredHandler onAchievementRegistered;
    public event QuestCompletedHandler onAchievementCompleted;

    public IReadOnlyList<Quest> ActiveQuests => activeQuests;
    public IReadOnlyList<Quest> CompletedQuests => completedQuests;
    public IReadOnlyList<Quest> ActiveAchievements => activeAchievements;
    public IReadOnlyList<Quest> CompletedAchievements => completedAchievements;

    private void Awake()
    {
        questDatabase = Resources.Load<QuestDatabase>("QuestDatabase");
        achievementDatabase = Resources.Load<QuestDatabase>("AchievementDatabase");

        if(!Load()) // 저장된 데이터가 없다면 업적에 등록
        {
            foreach (var achievement in achievementDatabase.Quests)
                Register(achievement);
        }
    }

    private void OnApplicationQuit()
    {
        isApplicationQuitting = true;
        Save();
    }

    public Quest Register(Quest quest)
    {
        var newQuest = quest.Clone();

        if(newQuest is Achievement)
        {
            newQuest.onCompleted += OnAchievementCompleted;

            activeAchievements.Add(newQuest);

            newQuest.OnRegister();
            onAchievementRegistered?.Invoke(newQuest);
        }
        else
        {
            newQuest.onCompleted += OnQuestCompleted;
            newQuest.onCanceled += OnQuestCanceled;

            activeQuests.Add(newQuest);
            newQuest.OnRegister();
            onQuestRegistered?.Invoke(newQuest);
        }

        return newQuest;
    }

    // 내부용
    private void ReceiveReport(List<Quest> quests, string category, object target, int successCount)
    {
        foreach (var quest in quests.ToArray())
            quest.ReceiveReport(category, target, successCount);
    }

    //외부용
    public void ReceiveReport(string category, object target, int successCount)
    {
        ReceiveReport(activeQuests, category, target, successCount);
        ReceiveReport(activeAchievements, category, target, successCount);
    }

    public void ReceiveReport(Category category, TaskTarget target, int successCount)
        => ReceiveReport(category.CodeName, target.Value, successCount);

    // 수업자료 보고 추가한 메서드
    public void CompleteWaitingQuests()
    {
        foreach (var quest in activeQuests.ToList())
        {
            if (quest.IsCompletable)
                quest.Complete();
        }
    }

    public bool ContainsInActiveQuests(Quest quest) => activeQuests.Any(x => x.CodeName == quest.CodeName);
    public bool ContainsInCompletedQuests(Quest quest) => completedQuests.Any(x => x.CodeName == quest.CodeName);
    public bool ContainsInActiveAchievements(Quest quest) => activeAchievements.Any(x => x.CodeName == quest.CodeName);
    public bool ContainsInCompletedAchievements(Quest quest) => completedAchievements.Any(x => x.CodeName == quest.CodeName);

    private void Save()
    {
        var root = new JObject();
        root.Add(kActiveQuestsSavePath, CreateSaveDatas(activeQuests));
        root.Add(kCompletedQuestsSavePath, CreateSaveDatas(completedQuests));
        root.Add(kActiveAchievementsSavePath, CreateSaveDatas(activeAchievements));
        root.Add(kCompletedAchievementsSavePath, CreateSaveDatas(completedAchievements));

        PlayerPrefs.SetString(kSaveRootPath, root.ToString());
        PlayerPrefs.Save();
    }

    private bool Load()
    {
        if (PlayerPrefs.HasKey(kSaveRootPath))
        {
            var root = JObject.Parse(PlayerPrefs.GetString(kSaveRootPath));

            LoadSaveDatas(root[kActiveQuestsSavePath], questDatabase, LoadActiveQuest);
            LoadSaveDatas(root[kCompletedQuestsSavePath], questDatabase, LoadCompletedQuest);
            LoadSaveDatas(root[kActiveAchievementsSavePath], achievementDatabase, LoadActiveQuest);
            LoadSaveDatas(root[kCompletedAchievementsSavePath], achievementDatabase, LoadCompletedQuest);

            return true;
        }
        else return false;

    }

    private JArray CreateSaveDatas(IReadOnlyList<Quest> quests)
    {
        var saveDatas = new JArray();
        foreach (var quest in quests)
        {
            if(quest.IsSaveable)
                saveDatas.Add(JObject.FromObject(quest.ToSaveData())); // SaveData를 Json형태로 변환하여 JsonArray에 넣어줌
        }
        return saveDatas;
    }

    private void LoadSaveDatas(JToken datasToken, QuestDatabase database, System.Action<QuestSaveData, Quest> OnSuccess)
    {
        var datas = datasToken as JArray;
        foreach (var data in datas)
        {
            var saveData = data.ToObject<QuestSaveData>();
            var quest = database.FindQuestBy(saveData.codeName);
            OnSuccess.Invoke(saveData, quest);
        }
    }

    private void LoadActiveQuest(QuestSaveData saveData, Quest quest)
    {
        var newQuest = Register(quest);
        newQuest.LoadFrom(saveData);
    }

    private void LoadCompletedQuest(QuestSaveData saveData, Quest quest)
    {
        var newQuest = quest.Clone();
        newQuest.LoadFrom(saveData);

        if (newQuest is Achievement)
            completedAchievements.Add(newQuest);
        else
            completedQuests.Add(newQuest);
    }

    #region Callback
    private void OnQuestCompleted(Quest quest)
    {
        activeQuests.Remove(quest);
        completedQuests.Add(quest);

        onQuestCompleted?.Invoke(quest);
    }

    private void OnQuestCanceled(Quest quest)
    {
        activeQuests.Remove(quest);
        onQuestCanceled?.Invoke(quest);

        Destroy(quest, Time.deltaTime);
    }

    private void OnAchievementCompleted(Quest achievement)
    {
        activeAchievements.Remove(achievement);
        completedAchievements.Add(achievement);

        onAchievementCompleted?.Invoke(achievement);
    }

    #endregion

}

QuestSystemSaveTest.cs

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

public class QuestSystemSaveTest : MonoBehaviour
{
    [SerializeField]
    private Quest quest;
    [SerializeField]
    private Category category;
    [SerializeField]
    private TaskTarget target;

    private void Start()
    {
        var questSystem = QuestSystem.Instance;

        if(questSystem.ActiveQuests.Count == 0)
        {
            Debug.Log("Register");
            var newQuest = questSystem.Register(quest);
        }
        else
        {
            questSystem.onQuestCompleted += (quest) =>
            {
                Debug.Log("Complete");
                PlayerPrefs.DeleteAll();
                PlayerPrefs.Save();
            };
        }
    }

    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
            QuestSystem.Instance.ReceiveReport(category, target, 1);
    }

}

이상입니다..