Unknown key in the template – 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 Check-Up which can resolve issues that cause many errors.

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

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up to analyze Elasticsearch configuration and help resolve this error.

Log Context

Log “unknown key [{}] in the template”classname  is PutIndexTemplateRequest.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

mapping((Map) entry1.getValue());
 } else if (name.equals("aliases")) {
 aliases((Map) entry.getValue());
 } else {
 throw new ElasticsearchParseException("unknown key [{}] in the template "; name);
 return this;


Try AutoOps to detect and fix issues in your cluster:

Analyze Your Cluster

Skip to content