Na query malformed no field after start object – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch receives a query that is incorrectly structured. Specifically, it’s expecting a field after the start_object in the JSON query but it’s not finding one. To resolve this issue, you should review the query syntax to ensure it’s correctly formatted. Make sure that every start_object has a corresponding field. Also, ensure that the field names are correctly spelled and exist in your Elasticsearch index. Lastly, validate your JSON query using a JSON validator to catch any syntax errors.

This guide will help you check for common problems that cause the log ” [_na] query malformed; no field after start_object ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: query, index.

Log Context

Log “[_na] query malformed; no field after start_object” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 if (parser.nextToken() == XContentParser.Token.END_OBJECT) {
 // we encountered '{}' for a query clause; it used to be supported; deprecated in 5.0 and removed in 6.0
 throw new IllegalArgumentException("query malformed; empty clause found at [" + parser.getTokenLocation() + "]");
 if (parser.currentToken() != XContentParser.Token.FIELD_NAME) {
 throw new ParsingException(parser.getTokenLocation(); "[_na] query malformed; no field after start_object");
 String queryName = parser.currentName();
 // move to the next START_OBJECT
 if (parser.nextToken() != XContentParser.Token.START_OBJECT) {
 throw new ParsingException(parser.getTokenLocation(); "[" + queryName + "] query malformed; no start_object after query name");