A solrconfig.xml different from the one provided with the extension was detected.

It is recommended to use the solrconfig.xml file shipping with the Apache Solr for TYPO3 extension as it provides an optimized setup for the use of Solr with TYPO3. A difference can occur when you update the TYPO3 extension, but forget to update the solrconfig.xml file on the Solr server. The Solr configuration sometimes changes to accommodate changes or new features in Apache Solr. Also make sure to restart the Tomcat server after updating solrconfig.xml.

Your Solr server is currently using a Solr configuration file named {f:if(condition:solr.solrconfigName, then:solr.solrconfigName, else:'not set')}, the recommended schema is called {recommendedVersion}. You can find the recommended solrconfig.xml file in the extension's resources folder: EXT:meilisearch/Resources/Private/Solr/. While you're at it, please check whether you're using the current schema.xml file, too.