It looks like your Elasticsearch cluster has the rest.action.multi.allow_explicit_index setting set to false, which prevents Kibana from making search requests. We use this ability to send a single request to Elasticsearch that searches multiple indexes so that when there are many panels on a dashboard they will load quickly and uniformly.
  
Unfortunately, until this issue is fixed you won't be able to use certain apps in Kibana, like Discover, Visualize and Dashboard.
rest.action.multi.allow_explicit_index: false from your Elasticsearch config file.