"Unable to connect to Elasticsearch" is missleading

[TiNico22]

Fatal Error
Unable to connect to Elasticsearch at "http://192.168.0.1:5601/elasticsearch"

ErrorAbstract@http://192.168.0.1:5601/index.js:73212:5
StatusCodeError@http://192.168.0.1:5601/index.js:73331:5
respond@http://192.168.0.1:5601/index.js:74468:9
checkRespForFailure@http://192.168.0.1:5601/index.js:74436:15
[198]</AngularConnector.prototype.request/<@http://192.168.0.1:5601/index.js:73159:7
qFactory/defer/deferred.promise.then/wrappedErrback@http://192.168.0.1:5601/index.js:20772:15
qFactory/defer/deferred.promise.then/wrappedErrback@http://192.168.0.1:5601/index.js:20772:15
qFactory/defer/deferred.promise.then/wrappedErrback@http://192.168.0.1:5601/index.js:20772:15
qFactory/createInternalRejectedPromise/<.then/<@http://192.168.0.1:5601/index.js:20905:13
$RootScopeProvider/this.$get</Scope.prototype.$eval@http://192.168.0.1:5601/index.js:21892:9
$RootScopeProvider/this.$get</Scope.prototype.$digest@http://192.168.0.1:5601/index.js:21704:15
$RootScopeProvider/this.$get</Scope.prototype.$apply@http://192.168.0.1:5601/index.js:21996:13
done@http://192.168.0.1:5601/index.js:17569:34
completeRequest@http://192.168.0.1:5601/index.js:17783:7
createHttpBackend/</xhr.onreadystatechange@http://192.168.0.1:5601/index.js:17726:1

Instead, the message should have been
Fatal Error
Unable to connect to Elasticsearch at "http://localhost:9200"

extract from my kibana.yml
'# The Elasticsearch instance to user for all your queries
elasticsearch: "http://localhost:9200"

The problem was identified because I have reinstalled everything because of #1561 #1557 workaround and my Elasticsearch was was not bind in localhost

[Kruiserx]

Same issue here, might be related to the routes setup in home.rb

  get "/config" do
    # Clone the settings object and change the elasticsearch attribute
    # to the proxy for elasticsearch
    data = settings.config.clone()
    data['elasticsearch'] = "#{request.scheme}://#{request.host}:#{request.port}/elasticsearch"
    json data
  end

that "/elasticsearch" doesn't seem right

[TiNico22]

In my case, it was "just" ES not binded at the address specified on the kibana.yml
That was my fault, but the error message is misleading

[rashidkpc]

An excellent point, we should communicating that elasticsearch is down, but not pointing you at the backend REST endpoint for troubleshooting.

[mydoghasworms]

For anyone else coming here for help: In my case the problem was caused by the HTTP_PROXY environment variable being set and the proxy being down. It's not the most obvious cause, and there is no obvious way from the error message that you would think to look at that.