Expected a string but found instead – 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 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 ” Expected a string but found instead ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: metadata.

Log Context

Log “Expected a string but found [{}] instead”classname  is TaskId.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

public static ContextParser parser() {
 return (p; c) -> {
 if (p.currentToken() == XContentParser.Token.VALUE_STRING) {
 return new TaskId(p.text());
 throw new ElasticsearchParseException("Expected a string but found [{}] instead"; p.currentToken());
 public String getNodeId() {
 return nodeId;


Watch product tour

Try AutoOps to find & fix Elasticsearch problems

Analyze Your Cluster
Skip to content