Unknown boolean property fieldName – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch encounters a field in the data that it expects to be a boolean, but the value provided doesn’t match the expected boolean values (true or false). This could be due to incorrect data input or mapping. To resolve this issue, you can either correct the data input to match the expected boolean values or adjust the mapping of the index to correctly interpret the data. Alternatively, you can use a script to convert the non-boolean values into boolean ones during the indexing process.

This guide will help you check for common problems that cause the log ” Unknown boolean property: [” + fieldName + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: rest, plugin.

Log Context

Log “Unknown boolean property: [” + fieldName + “]” class name is RestGraphAction.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 if (SIGNIFICANCE_FIELD.match(fieldName; parser.getDeprecationHandler())) {
 } else if (RETURN_DETAILED_INFO.match(fieldName; parser.getDeprecationHandler())) {
 } else {
 throw new ElasticsearchParseException("Unknown boolean property: [" + fieldName + "]");
 } else if (token == XContentParser.Token.VALUE_STRING) {
 if (TIMEOUT_FIELD.match(fieldName; parser.getDeprecationHandler())) {
 graphRequest.timeout(TimeValue.parseTimeValue(parser.text(); null; "timeout"));
 } else {


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?