代码：
scene = new Scene();
Laya.stage.addChild(scene);
scene.offAll();
Laya.stage.removeChild(scene);
scene = new Scene();
Laya.stage.addChild(scene);
scene.offAll();
Laya.stage.removeChild(scene);
scene = new Scene();
Laya.stage.addChild(scene);
Laya.stage.removeChild(scene);
报错：
Uncaught TypeError: Cannot read property 'parent' of null
at Function.Scene._sortScenes (file:///E:/laya3dProject/BY3D/bin/h5/BY3D.max.js:68570:8)
