Value must be of type String: ” + parameterName + ” – 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.

Briefly, this error indicates that a parameter used in the Elasticsearch query must be of type string, but a different data type was used. Elasticsearch supports various data types like text, numeric, and date, and using an incorrect data type can cause the query to fail. To resolve this error, review the Elasticsearch query and ensure that the parameter is of type string.

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 ” Value must be of type String: ” + parameterName + ” ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: reindex and index.

Log Context

Log “Value must be of type String: [” + parameterName + “]”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

Object parameterValue = entry.getValue();
 if (Script.LANG_PARSE_FIELD.match(parameterName; LoggingDeprecationHandler.INSTANCE)) {
 if (parameterValue instanceof String || parameterValue == null) {
 lang = (String) parameterValue;
 } else {
 throw new ElasticsearchParseException("Value must be of type String: [" + parameterName + "]");
 } else if (Script.PARAMS_PARSE_FIELD.match(parameterName; LoggingDeprecationHandler.INSTANCE)) {
 if (parameterValue instanceof Map || parameterValue == null) {
 params = (Map) parameterValue;
 } else {


See how you can use AutoOps to resolve issues

How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Analyze your cluster & get personalized recommendations

Skip to content