Failed to retrieve users expecting an object but got – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-7.17

Briefly, this error occurs when Elasticsearch expects to receive user data in a specific object format, but the received data is in a different format. This could be due to incorrect data structure or a mismatch in the expected data type. To resolve this issue, you can: 1) Check and correct the data structure being sent to Elasticsearch. 2) Validate the data type before sending it to Elasticsearch. 3) Update the Elasticsearch mapping to match the data type being sent.

This guide will help you check for common problems that cause the log ” failed to retrieve users; expecting an object but got: ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “failed to retrieve users; expecting an object but got:” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 } else {
 throw new ElasticsearchException("failed to retrieve users; expecting an object but got: " + token);
 terminal.println("found existing users: " + existingUsers);
 return existingUsers;