Application does not run on IE9

[warjohn123]

When I npm start the application, on IE9 it has this error:

webpack-hot-middleware's client requires EventSource to work. You should include a polyfill if you want to support this browser: https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events#Tools

[fesor]

You should include a polyfill if you want to support this browser: https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events#Tools

Basicly this is the answer. Just add this polyfil only for your dev builds. Or you could just disable wepack-hot-middleware.