Failed to query elasticsearch for previous even

I'm using logstash 2.3.0, we are using elastisearch correlation in my config file. While processing facing issue on correlation and its throwing below error,
<TypeError: can't convert nil into String>, :level=>:warn}
Failed to query elasticsearch for previous event {:query=>"type:vehicle_log AND vehicle_modelNumber:\"6948\" AND vehicle_modelYear:\"2016\"v AND vehicle_phaseCode:\"G\"", :event=>2016-04-08T15:30:06.406Z <s:Envelope xmlns:s="">

This is my correlation:
elasticsearch {
hosts => ["http://xx.xx.xx.xx:9200"]
query => "type:dealer_log AND dlr_dlrCode:"%{[dlr_tradefrm_dlrno]}""
fields => [
#fail_on_error => "false"

Im trying to correlate the field from existing index to current processing index. Please help us to resolve it.

Is there anything in the ES logs at the same time?