Don't know what is producing these error ... any ideas?

Error: Request to Elasticsearch failed: {error:{}}
    at http://localhost:5601/bundles/commons.bundle.js:3:4901144
    at Function._module.service.Promise.try (http://localhost:5601/bundles/commons.bundle.js:3:2504121)
    at http://localhost:5601/bundles/commons.bundle.js:3:2503495
    at Array.map (<anonymous>)
    at Function._module.service.Promise.map (http://localhost:5601/bundles/commons.bundle.js:3:2503452)
    at callResponseHandlers (http://localhost:5601/bundles/commons.bundle.js:3:4899658)
    at http://localhost:5601/bundles/commons.bundle.js:3:4882019
    at processQueue (http://localhost:5601/built_assets/dlls/vendors.bundle.dll.js:435:204190)
    at http://localhost:5601/built_assets/dlls/vendors.bundle.dll.js:435:205154
    at Scope.$digest (http://localhost:5601/built_assets/dlls/vendors.bundle.dll.js:435:215159)

I supposed this is a Kibana trace?

So may be ask in #kibana forum instead?

Otherwise, have a look at elasticsearch logs. You might see interesting things hopefully.