在Unity中使用DoTWeen时出错

我有一个使用 DoTween 为窗口及其元素设置动画的脚本。但是控制台有一个我不明白的错误：

UnityException：不允许从 MonoBehaviour 构造函数（或实例字段初始值设定项）调用 get_isPlaying，请改为在 Awake 或 Start 中调用它。从游戏对象“Button（Legacy）”上的 MonoBehaviour“FadePanel”调用。有关详细信息，请参阅 Unity 手册中的“脚本序列化”页面。 DG.Tweening.DOTween.InitCheck () (位于 D:/DG/_Develop/__UNITY_ASSETS/_Demigiant/__DOTween/_DOTween.Assembly/DOTween/DOTween.cs:1128) DG.Tweening.DOTween.Sequence () (位于D:/DG/_Develop/__UNITY_ASSETS/_Demigiant/__DOTween/_DOTween.Assembly/DOTween/DOTween.cs:732) FadePanel..ctor () (位于 Assets/Assets1/scripts/FadePanel.cs:21)

---------------->

脚本本身：

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


public class FadePanel : MonoBehaviour
{
    public CanvasGroup alfaGroup;
    public RectTransform BuyPanel;
    private RectTransform shopButt;
    Vector2 TargetPos;
    Vector2 StartPos;
    Vector2 targBut;

    public List<RectTransform> tranf = new List<RectTransform>();

    private bool isOpen = false;

    Sequence anim = DOTween.Sequence();

    private void Awake()
    {
        TargetPos = BuyPanel.transform.position;
        StartPos = new Vector2(-Screen.width / 2, StartPos.x);

        targBut = new Vector2(90, 177);
    }

    private void OnMouseDown()
    {
        if (!isOpen)
        {
            isOpen = true;

            anim
                .Append(BuyPanel.DOAnchorPos(TargetPos, 1f).From(StartPos))
                .Join(alfaGroup.DOFade(1, 1f).From(0))
                .Join(shopButt.DOAnchorPos(targBut, 1f).From(shopButt.position));

            IconsUp();
        }
        else
        {
            anim
                .Append(alfaGroup.DOFade(0, 1f).From(1))
                .Join(shopButt.DOAnchorPos(shopButt.position, 1f).From(targBut));
        }
    }

    private void IconsUp()
    {
        for (int i = 0; i < tranf.Count; i++)
        {
            anim
                .Append(tranf[i].DOScale(1, 0.5f).From(0));
        }
    }

}