Unexpected token token after fieldName – How to solve this OpenSearch exception

Opster Team

Aug-23, Version: 1-2.9

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Briefly, this error occurs when OpenSearch encounters an unexpected token after a field name in a query. This usually happens due to a syntax error, such as a missing comma, bracket, or quotation mark. To resolve this issue, carefully review your query syntax. Ensure that all field names are correctly formatted and enclosed in quotation marks, and that commas and brackets are properly placed. Also, check for any extraneous characters that may have been accidentally included in the query. Correcting these errors should resolve the issue.

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

Log Context

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

 if (suggestionName == null) {
 throw new IllegalArgumentException("suggestion must have name");
 suggestBuilder.addSuggestion(suggestionName; SuggestionBuilder.fromXContent(parser));
 } else {
 throw new ParsingException(parser.getTokenLocation(); "unexpected token [" + token + "] after [" + fieldName + "]");
 return suggestBuilder;


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