[LayaAir 2.0]unity导出粒子特效laya加载报错。

版本2.1.0 插件也是2.1.0.
 laya.d3.js:1870 Uncaught TypeError: Cannot read property 'path' of undefined
    at Function.Laya3D._getSprite3DHierarchyInnerUrls (laya.d3.js:1870)
    at Function.Laya3D._getSprite3DHierarchyInnerUrls (laya.d3.js:1917)
    at Loader.Laya3D._onHierarchylhLoaded (laya.d3.js:1934)
    at EventHandler.__proto.runWith (laya.core.js:2062)
    at Loader.__proto.event (laya.core.js:1818)
    at Loader.__proto.complete (laya.core.js:23571)
    at Loader.__proto.onLoaded (laya.core.js:23519)
    at EventHandler.__proto.runWith (laya.core.js:2061)
    at HttpRequest.__proto.event (laya.core.js:1818)
    at HttpRequest.__proto.complete (laya.core.js:23140)