1.IE下报错Unhandled promise rejection ReferenceError: “Promise”未定义

解决：

1. npm i babel-polyfill -S，
2. 在main.js中引用babel-polyfill import 'babel-polyfill'

2.上步骤后继续报错polyfill-eventsource added missing EventSource to window

解决：

1. npm i event-source-polyfill -S
2. 在main.js中babel-polyfill后继续引用 import 'event-source-polyfill'