We have a single node of Kibana 5.1 and two nodes of Elasticsearch 5.1. It has been deployed in production and just one admin uses the console. So there's hadly any load. Just a few queries are performed in a day as of now.
Still, even in this breezy situation Kibana keeps on crashing. I have enabled all logging options
Before crashing Kibana logged a warning that it's "Unable to revive connection" to elastic search node. And another warning saying "No living connections". That was the last log after which it had crashed.
As for configuration: , Kibana is running on SSL. Other than this no other configurations have been added.