Kibana error Content-type header [application/x-ndjson; charset=UTF-8] is not supported

Hi.

I am sending a log (from a kannel instance) through filebeat to logstash and then to elastic search cluster.

All components are in the latest version (6.0.0) and I am getting the error "Content-type header [application/x-ndjson; charset=UTF-8] is not supported" in Kibana when I click in discover or even try to create a graphic in visualize.

The kibana has discovered all the fields in the created Index.

It is true that the messages have some UTF-8 (latin with accents) characters.

I haven't installed X-Pack. All of the components were installed with rpm in a CentOS environment.

Can you tell me what could the error be?

Regards

Ricardo

Apparently is a problem of the browser. With Firefox 45 it gives this error... with Chrome it doesn't give.

FYI, Firefox 47 is over a year out of date. I'm on 57 now. Maybe you have it set to not get updates?