Fixing a Kibana Error - Discover: An error occurred with your request. Reset your inputs and try again.

Problem

One day, when I accessed Kibana > Discover, I ran into the following error,
and Searching could no longer complete.

Checking the ElasticSearch logs

tail -f /var/log/elasticsearch/elasticsearch.log

Failed to execute [org.elasticsearch.action.search.SearchRequest@8307e49] while moving to second phase
java.lang.ClassCastException: java.lang.Long cannot be cast to org.apache.lucene.util.BytesRef
        at org.apache.lucene.search.FieldComparator$TermOrdValComparator.compareValues(FieldComparator.java:902)
        at org.apache.lucene.search.TopDocs$MergeSortQueue.lessThan(TopDocs.java:172)
        at org.apache.lucene.search.TopDocs$MergeSortQueue.lessThan(TopDocs.java:120)
        at org.apache.lucene.util.PriorityQueue.upHeap(PriorityQueue.java:225)
        at org.apache.lucene.util.PriorityQueue.add(PriorityQueue.java:133)
        at org.apache.lucene.search.TopDocs.merge(TopDocs.java:234)
        at org.elasticsearch.search.controller.SearchPhaseController.sortDocs(SearchPhaseController.java:239)
        at org.elasticsearch.action.search.type.TransportSearchQueryThenFetchAction$AsyncAction.moveToSecondPhase(TransportSearchQueryThenFetchAction.java:89)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.innerMoveToSecondPhase(TransportSearchTypeAction.java:403)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.onFirstPhaseResult(TransportSearchTypeAction.java:202)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction$1.onResult(TransportSearchTypeAction.java:178)
        at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction$1.onResult(TransportSearchTypeAction.java:175)
        at org.elasticsearch.search.action.SearchServiceTransportAction$23.run(SearchServiceTransportAction.java:568)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)

It turned out to be a bug where a cast was failing.

I figured maybe the mapping wasn’t working correctly,
so I started changing various settings under that assumption and eventually arrived at this fix.

Solution

1. Kibana > Settings > Advanced
2. Change sort:options from {“unmapped_type”: “boolean”} to {“ummapped_type”: “date” }

That fixed it!

It was also recorded on GitHub as a closed issue.

Auto detect field type when sorting on unmapped_type fields