Malformed regular expression file expecting object – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

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Briefly, this error occurs when Elasticsearch encounters an incorrectly formatted regular expression file. It expects an ‘object’ type but is receiving something different. To resolve this issue, you can: 1) Review the regular expression file for any syntax errors or incorrect formatting. 2) Ensure that the file is correctly structured as an ‘object’. 3) Validate the regular expression file using a JSON validator to catch any potential errors. 4) Check the Elasticsearch version compatibility with the regular expression file, as different versions may have different requirements.

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This guide will help you check for common problems that cause the log ” malformed regular expression file; expecting ‘object’ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .

Log Context

Log “malformed regular expression file; expecting ‘object'” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 throw new ElasticsearchParseException("malformed regular expression file; should continue with 'array' after 'object'");
 }  token = yamlParser.nextToken();
 if (token != XContentParser.Token.START_OBJECT) {
 throw new ElasticsearchParseException("malformed regular expression file; expecting 'object'");
 }  while (token == XContentParser.Token.START_OBJECT) {
 token = yamlParser.nextToken();


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