Failed to execute phase [query_fetch]

Yesterday after rebooting linux server, I am getting this error in my website log.

2015-11-27 16:01:38,228 ERROR error while quering elasticesearch
ErrorId: ccad9203-0bab-4021-ba53-f407813bdec7.
Elasticsearch.Net.ElasticsearchServerException: Failed to execute phase [query_fetch], all shards failed; shardFailures {[eyRBaaVLRHSSLdraTvyTsw][gts][0]: SearchParseException[[sts][0]: from[0],size[20]: Parse Failure [Failed to parse source [{
"from": 0,
"size": 20,
"suggest": {
"SuggestUserLocation": {
"text": "",
"completion": {
"field": "locationSuggest"
}
}
}
}]]]; nested: ClassCastException[org.elasticsearch.index.mapper.core.StringFieldMapper cannot be cast to org.elasticsearch.index.mapper.core.CompletionFieldMapper]; }

Thank you for looking.

Anyone?

No one has come across this problem before?