[]微信小游戏报错 the .lh file root type must be Scene

引擎版本1.7.17beta
private screen3DPath: string = "res/layaScene/xiangsuqiche.ls";

public LoadScene3D(): Laya.Scene {
console.log("screen#DPath = " + this.screen3DPath);
let scene: Laya.Scene = Laya.Scene.load(this.screen3DPath);
Laya.stage.addChildAt(scene, 0);
this.InitCamera(scene);
return scene;
}

微信小游戏报错
Scene: the .lh file root type must be Scene,please use other function to load this file.;at api readFile success callback function
Error: Scene: the .lh file root type must be Scene,please use other function to load this file.
at Scene.__proto.onAsynLoaded (http://127.0.0.1:62629/game/code.js:81644:10)
at ResInfo.onLoaded (http://127.0.0.1:62629/game/code.js:12995:61)
at EventHandler.__proto.runWith (http://127.0.0.1:62629/game/code.js:711:59)
at ResInfo.__proto.event (http://127.0.0.1:62629/game/code.js:483:28)
at LoaderManager.__proto._endLoad (http://127.0.0.1:62629/game/code.js:13152:11)
at Loader.onLoaded (http://127.0.0.1:62629/game/code.js:13128:10)
at EventHandler.__proto.runWith (http://127.0.0.1:62629/game/code.js:711:59)
at Loader.__proto.event (http://127.0.0.1:62629/game/code.js:483:28)
at Loader.__proto.endLoad (http://127.0.0.1:62629/game/code.js:12740:8)
at Function.Loader.checkNext (http://127.0.0.1:62629/game/code.js:12769:40)