Unexpected token token – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch encounters an unexpected token in the query. This could be due to a syntax error, such as a missing or misplaced bracket, comma, or quotation mark. To resolve this issue, you should carefully review your query for any syntax errors. Make sure all brackets, commas, and quotation marks are correctly placed. Also, ensure that the field names and values in your query match those in your Elasticsearch index. If the error persists, try running a simpler query to isolate the problem.

This guide will help you check for common problems that cause the log ” unexpected token [” + token + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: query, index.

Log Context

Log “unexpected token [” + token + “]” class name is ConstantScoreQueryBuilder.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 "[constant_score] query does not support [" + currentFieldName + "]"
 } else {
 throw new ParsingException(parser.getTokenLocation(); "unexpected token [" + token + "]");
 if (queryFound == false) {
 throw new ParsingException(parser.getTokenLocation(); "[constant_score] requires a 'filter' element");