Kibana Discover tab is not loading

In our dev environment kibana discover is not loading. All the other tabs are working fine. Any solutions? we have tried different time ranges.

What are you seeing? Can you show an image?
Have you checked the browsers developer console to see what is happening?

We are getting a white screen with following error in the console.

Can you check the ES logs at the same time to see if there is anything? (there should be)

What version of Elasticsearch and Kibana are you using?

Elasticsearch - 2.3.4
Kibana - 4.5.2

ES log error:
[action.admin.indices.mapping.put] [devdata-0] failed to put mappings on indices [[.kibana]], type [search]
java.lang.IllegalArgumentException: mapper [hits] cannot be changed from type [long] to [int]
at org.elasticsearch.index.mapper.MappedFieldType.checkTypeName(
at org.elasticsearch.index.mapper.MappedFieldType.checkCompatibility(
at org.elasticsearch.index.mapper.core.NumberFieldMapper$NumberFieldType.checkCompatibility(
at org.elasticsearch.index.mapper.FieldTypeLookup.checkCompatibility(
at org.elasticsearch.index.mapper.FieldTypeLookup.copyAndAddAll(
at org.elasticsearch.index.mapper.MapperService.merge(
at org.elasticsearch.index.mapper.MapperService.merge(
at org.elasticsearch.cluster.metadata.MetaDataMappingService$PutMappingExecutor.applyRequest(
at org.elasticsearch.cluster.metadata.MetaDataMappingService$PutMappingExecutor.execute(
at org.elasticsearch.cluster.service.InternalClusterService.runTasksForExecutor(
at org.elasticsearch.cluster.service.InternalClusterService$
at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.runAndClean(
at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$
at java.util.concurrent.ThreadPoolExecutor.runWorker(
at java.util.concurrent.ThreadPoolExecutor$

Started getting Disover after deleting .kibana index from elasticsearch.
Not sure how it works though. Also not sure the reason for not loading the discover page.

Also get a backup of your dashboards too since after deleting .kibana index all will be removed.