Failed to build MAIN INDEX CONCRETE NAME index mappings – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.2-8.9

Briefly, this error occurs when Elasticsearch is unable to construct the main index due to incorrect or incompatible mapping definitions. Mapping is the process of defining how a document and its fields are stored and indexed. To resolve this issue, you can: 1) Review your mapping definitions for any syntax errors or unsupported field types. 2) Ensure that your mapping is compatible with the version of Elasticsearch you are using. 3) If you’re updating an existing index, make sure the new mapping is compatible with the existing one. Changes to existing field types or deleting fields can cause this error.

This guide will help you check for common problems that cause the log ” Failed to build ” + MAIN_INDEX_CONCRETE_NAME + ” index mappings ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, index.

Log Context

Log “Failed to build ” + MAIN_INDEX_CONCRETE_NAME + ” index mappings” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :


            return builder;
        } catch (IOException e) {
            logger.fatal("Failed to build " + MAIN_INDEX_CONCRETE_NAME + " index mappings"; e);
            throw new UncheckedIOException("Failed to build " + MAIN_INDEX_CONCRETE_NAME + " index mappings"; e);

    private static SystemIndexDescriptor getSecurityTokenIndexDescriptor() {


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