Could not find plugin class ” + className + ” – How to solve this Elasticsearch error

Opster Team

March-22, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many configuration errors.

To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.

This guide will help you check for common problems that cause the log ” Could not find plugin class ” + className + ” ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugins, plugin.

Log Context

Log “Could not find plugin class [” + className + “]”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

private Class loadPluginClass(String className; ClassLoader loader) {
 try {
 return Class.forName(className; false; loader).asSubclass(Plugin.class);
 } catch (ClassNotFoundException e) {
 throw new ElasticsearchException("Could not find plugin class [" + className + "]"; e);
 private Plugin loadPlugin(Class pluginClass; Settings settings; Path configPath) {
 final Constructor[] constructors = pluginClass.getConstructors();


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