ElasticSearch "Can't get text on a VALUE_NULL at 1:60"
<p>When running queries on one of my indexes I get an error on Elastic.</p>

<pre><code>{
  "error" : {
    "root_cause" : [ {
      "type" : "illegal_state_exception",
      "reason" : "Can't get text on a VALUE_NULL at 1:60"
    } ],
    "type" : "search_phase_execution_exception",
    "reason" : "all shards failed",
    "phase" : "query",
    "grouped" : true,
    "failed_shards" : [ {
      "shard" : 0,
      "index" : "someIndexName",
      "node" : "sfsfd5sdf",
      "reason" : {
        "type" : "illegal_state_exception",
        "reason" : "Can't get text on a VALUE_NULL at 1:60"
      }
    } ]
  },
  "status" : 500
}
</code></pre>

<p>My configuration: </p>

<pre><code>{
  "cluster_name" : "clusterName",
  "status" : "green",
  "number_of_nodes" : 2,
  "number_of_data_nodes" : 2,
  "active_primary_shards" : 16,
  "active_shards" : 32,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "delayed_unassigned_shards" : 0,
  "number_of_pending_tasks" : 0,
  "number_of_in_flight_fetch" : 0,
  "task_max_waiting_in_queue_millis" : 0,
  "active_shards_percent_as_number" : 100.0
}


"version" : {
    "number" : "2.3.1",
    "build_hash" : "bd980929010aef404e7cb0843e61d0665269fc39",
    "build_timestamp" : "2016-04-04T12:25:05Z",
    "build_snapshot" : false,
    "lucene_version" : "5.5.0"
},
</code></pre>

<p>Offending query example:</p>

<pre><code>{
   "fields": ["id", "coordsField",null],
   "query": {
       "filtered": {
           "query": {
               "bool": {
                   "must": [],
                   "must_not": [],
                   "should": [],
                   "filter": [{
                       "query_string": {
                           "default_field": "type",
                           "query": "type1 type2 type3 type4 type5"
                       }
                   }, {
                       "or": [{
                           "exists": {
                               "field": "field0"
                           }
                       },
...
                       {
                           "exists": {
                               "field": "field6"
                           }
                       }]
                   }, {
                       "geo_bounding_box": {
                           "type": "indexed",
                           "coordsField": {
                               "top_left": {
                                   "lat": 123.471723,
                                   "lon": -123.173828
                               },
                               "bottom_right": {
                                   "lat": 123.937079,
                                   "lon": 123.82373
                               }
                           }
                       }
                   }, {
                       "exists": {
                           "field": "field7"
                       }
                   }, {
                       "exists": {
                           "field": "field8.prop"
                       }
                   }],
                   "minimum_should_match": 1
               }
           },
           "filter": {
               "geo_bounding_box": {
                   "coords.current.geometry.coordinates": {
                       "bottom_left": [-0.13623046875, 51.50600814450517],
                       "top_right": [-0.08349609375, 51.53881991608289]
                   },
                   "type": "indexed"
               }
           }
       }
   },
   "size": 0,
   "aggregations": {
       "zoom1": {
           "geohash_grid": {
               "field": "coordsField",
               "size": 5000,
               "precision": 7
           },
           "aggs": {
               "geohash": {
                   "top_hits": {
                       "sort": {
                           "id": {
                               "order": "desc",
                               "ignore_unmapped": true
                           }
                       },
                       "_source": false,
                       "fielddata_fields": ["id", "coordsField", null],
                       "size": 1
                   }
               }
           }
       }
   }
</code></pre>

<p>}</p>

<p>Googled but didn't find anything related. Where should I start searching to get an idea for the cause ?</p>