Could you open browser's dev tools and see if there's an error in the console? Also you should be able to see the network request that failed, what was the request and response? Without any stack trace or network errors I'm at a bit of a loss. Is there anything unusual about your setup, or steps that you can think of that would help me reproduce?
https://www.elastic.co/guide/en/kibana/current/getting-started.html
Cheers
Rashmi