Key settings must be an object – How to solve this Elasticsearch error

Key settings must be an object – 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 ” key settings must be an object ” 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: admin and indices.

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”key [settings] must be an object”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

public CreateIndexRequest source(Map source; DeprecationHandler deprecationHandler) {
  for (Map.Entry entry : source.entrySet()) {
  String name = entry.getKey();
  if (SETTINGS.match(name; deprecationHandler)) {
  if (entry.getValue() instanceof Map == false) {
  throw new ElasticsearchParseException("key [settings] must be an object");
  settings((Map) entry.getValue());
  } else if (MAPPINGS.match(name; deprecationHandler)) {
  Map mappings = (Map) entry.getValue();
  for (Map.Entry entry1 : mappings.entrySet()) {


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

Analyze your cluster