出现了这个错误：
TypeError: Cannot read property ‘clip’ of null
at Object.isRecordCurrentClip (D:\CocosCreator_2.3.1\resources\app.asar\editor\page\scene-utils\utils\animation.js:1:8569)
at Object.setProperty (D:\CocosCreator_2.3.1\resources\app.asar\editor\page\scene-utils\utils\scene.js:1:8982)
at HTMLElement.set-property (D:\CocosCreator_2.3.1\resources\app.asar\editor\builtin\scene\panel\messages\scene-operation.js:1:1070)
at Object.e._dispatch (D:\CocosCreator_2.3.1\resources\app.asar\editor-framework\lib\renderer\panel.js:1:1876)
at EventEmitter. (D:\CocosCreator_2.3.1\resources\app.asar\editor-framework\lib\renderer\ipc.js:1:2952)
at EventEmitter.emit (events.js:194:13)
at EventEmitter.emit (domain.js:469:20)
at EventEmitter.topLevelDomainCallback (domain.js:124:23)
只能选中一个动画，另一个无法编辑