Invalid unicode character code – 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 ” Invalid unicode character code ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, parser.

Log Context

Log “Invalid unicode character code [{}]”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

if (code >= 0xD800 && code <= 0xDFFF) {
 throw new ParsingException(source; "Invalid unicode character code; [{}] is a surrogate code"; hex);
 return String.valueOf(Character.toChars(code));
 } catch (IllegalArgumentException e) {
 throw new ParsingException(source; "Invalid unicode character code [{}]"; hex);
 private static void checkForSingleQuotedString(Source source; String text; int i) {
 if (text.charAt(i) == '\'') {


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