loader.loadRes回调了completeCallback，并且返回prefab，但是用返回的prefab调用instatialize时，报错误：
Warning 3700, please go to https://github.com/cocos-creator/engine/blob/master/EngineErrorMap.md#3700 to see details.
E/cocos js error:: assets/src/jsb_polyfill.js line:5971 msg:TypeError: this.data._instantiate is not a function
大家碰到过类似问题么？大牛有什么建议，万分感谢。