Expected array for ” + field + ” – How to solve this Elasticsearch error

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Expected array for ” + field + ” – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues that cause many errors.

This guide will help you check for common problems that cause the log ” expected array for ” + field + ” ” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: repositories.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to pinpoint the cause of many errors and provides suitable actionable recommendations how to resolve them (free tool that requires no installation).

Log Context

Log”expected array for [” + field + “]”classname  is RepositoryData.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

if (metaGenerations.isEmpty() == false) {
  indexMetaLookup.put(snapshotId; metaGenerations);
  } else {
  throw new ElasticsearchParseException("expected array for [" + field + "]");
  } else if (INDICES.equals(field)) {
  if (parser.nextToken() != XContentParser.Token.START_OBJECT) {
  throw new ElasticsearchParseException("start object expected [indices]");


Run the Check-Up to get a customized report like this:

Analyze your cluster