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

Opster Team

July-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” key settings must be an object ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: admin and indices.

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()) {


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