Expecting Json Field name token after the Start Object token – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

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Briefly, this error occurs when Elasticsearch receives a JSON object that is not properly formatted. It expects a field name after the start of an object, but it’s not finding one. This could be due to missing quotes around field names, missing colons after field names, or incorrect nesting of objects. To resolve this issue, you should validate your JSON object using a JSON validator. Make sure all field names are quoted, all field names are followed by a colon, and objects are correctly nested.

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This guide will help you check for common problems that cause the log ” Expecting Json Field name token after the Start Object token ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “Expecting Json Field name token after the Start Object token” classname is ProcessResultsParser.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                return false;
            if (token == XContentParser.Token.END_ARRAY) {
                return false;
            } else if (token != XContentParser.Token.START_OBJECT) {
                logger.error("Expecting Json Field name token after the Start Object token");
                throw new ElasticsearchParseException("unexpected token [" + token + "]");
            return true;


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