[LayaAirIDE 2.0]ReferenceError: Loader is not defined 搞不懂引擎原生的也会报这个错？

onEnable() {
//戏控制脚本引用，避免每次获取组件带来不必要的性能开销
thi
 
s._loveControl = this.getComponent(LoveControl); 
//点击提示文字，开始游戏
this.label_start.on(Laya.Event.CLICK, this, this.onTipClick);
//this._loveControl.startGame(); 
//点击重置按钮，重新开始
this.button_reset.on(Laya.Event.CLICK, this, this.onClickReset); 
let partPath = "res/aixin_bao.part";
Laya.loader.load(partPath, Laya.Handler.create(this, this.onAssetsLoaded), null, Loader.JSON);
} 
onAssetsLoaded(settings) {
        // 当load数组的时候，回调函数传入的参数不再是资源，可以通过以下方法获取资源
        // let settings = Laya.loader.getRes(partPath); 
        // 创建 Particle2D 实例
        let partIns = new Laya.Particle2D(settings);
        Laya.stage.addChild(partIns);
        // 开始发射粒子
        partIns.emitter.start();
        // 播放
        partIns.play(); 
        partIns.x = Laya.stage.width / 2; 
        partIns.y = Laya.stage.height / 2;
    } 
 
 
 
报错如下：
ReferenceError: Loader is not defined
preload.js:55
    at LoveView.onEnable (file:///D:/laya/myLaya/myZootopia/bin/js/bundle.js:683:94)
    at LoveView.__proto._activeHierarchy (file:///D:/laya/myLaya/myZootopia/bin/libs/laya.core.js:21411:8)
    at LoveView.__proto._processActive (file:///D:/laya/myLaya/myZootopia/bin/libs/laya.core.js:21386:8)
    at LoveView.__proto._onAdded (file:///D:/laya/myLaya/myZootopia/bin/libs/laya.core.js:21475:59)
    at LoveView.__proto._setParent (file:///D:/laya/myLaya/myZootopia/bin/libs/laya.core.js:21140:10)
    at LoveView.__proto._setParent (file:///D:/laya/myLaya/myZootopia/bin/libs/laya.core.js:26903:31)