You are looking at preliminary documentation for a future release. Not what you want? See the current release documentation.
In 5.1.1, an
UnhandledPromiseRejectionWarningoccurs and Kibana displays an Internal Server Error.
If the Security plugin is enabled in Elasticsearch but disabled in Kibana, you must
Otherwise, Kibana cannot connect to Elasticsearch.
Intro to Kibana
ELK for Logs & Metrics