动画编辑器经常出现这个错误，Cannot read property ‘_prefab’ of null

Creator 2.x
#1

TypeError: Cannot read property ‘_prefab’ of null
at Object.PrefabUtils.confirmEditingPrefabSynced (D:\CocosCreator\resources\app.asar\editor\page\scene-utils\prefab-utils.js:1:9784)
at HTMLElement.confirmCloseScene (file:///D:/CocosCreator/resources/app.asar/editor/builtin/scene/panel/scene.js:1:3105)
at HTMLElement.run (file:///D:/CocosCreator/resources/app.asar/editor/builtin/scene/panel/scene.js:1:951)
at EventEmitter.ipcRenderer.on (D:\CocosCreator\resources\app.asar\editor-framework\lib\renderer\panel.js:1:2791)
at emitThree (events.js:116:13)
at EventEmitter.emit (events.js:197:7)

动画编辑器，稍微操作下，经常出现这种问题，场景无法保存，我看论坛说1.5.1就出现了，现在1.9.1了，还有这个问题，引擎同学们，安排解决一下？

#2

请问有重现方法吗？1.9.2 和 1.9.3 更新了动画编辑器，麻烦升级到 1.9.3 试试？