[0]底层渲染报错，原因未知，偶现

TypeError: Cannot read property '_getSource' of null
at Context.drawTriangles (laya.core-56a0e.js:1:260080)
at DrawTrianglesCmd.run (laya.core-56a0e.js:1:288118
at Graphics._renderAll (laya.core-56a0e.js:1:300421)
at RenderSprite.transform_drawLayaGL [as _fun] (laya.core-56a0e.js:1:131686)
at SpineSkeleton.render (laya.core-56a0e.js:1:335975)
at RenderSprite._children (laya.core-56a0e.js:1:139465)
at Box.render (laya.core-56a0e.js:1:335975)
at RenderSprite._children (laya.core-56a0e.js:1:139465)
at Sprite.render (laya.core-56a0e.js:1:335975)
at RenderSprite._children (laya.core-56a0e.js:1:139465)