Malformed regular expression file should continue with field name after array – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Before you dig into reading this guide, have you tried asking OpsGPT what this log means? You’ll receive a customized analysis of your log.

Try OpsGPT now for step-by-step guidance and tailored insights into your Elasticsearch operation.

Briefly, this error occurs when Elasticsearch encounters a malformed regular expression file. It expects a ‘field_name’ after ‘array’ but it’s not present. This could be due to a syntax error or incorrect formatting in the regular expression file. To resolve this issue, you should review the regular expression file and correct any syntax or formatting errors. Ensure that the ‘field_name’ follows ‘array’ as expected. Additionally, validate your regular expression file using a regex validator to catch any hidden errors.

For a complete solution to your to your search operation, try for free AutoOps for Elasticsearch & OpenSearch . With AutoOps and Opster’s proactive support, you don’t have to worry about your search operation – we take charge of it. Get improved performance & stability with less hardware.

This guide will help you check for common problems that cause the log ” malformed regular expression file; should continue with ‘field_name’ after ‘array’ ” 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; should continue with ‘field_name’ after ‘array'” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 while (token == XContentParser.Token.START_OBJECT) {
 token = yamlParser.nextToken();  if (token != XContentParser.Token.FIELD_NAME) {
 throw new ElasticsearchParseException("malformed regular expression file; should continue with 'field_name' after 'array'");
 }  Map regexMap = new HashMap<>();
 for (; token == XContentParser.Token.FIELD_NAME; token = yamlParser.nextToken()) {
 String fieldName = yamlParser.currentName();


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?