Hello, it seems an  mismatch of schema file provided by dovecot-2.3.5.2 

[root@mail conf]# pwd
/var/solr/data/dovecot/conf

# Below solrconfig.xml is from Solr-8.0.0.

[root@mail conf]# grep text_general solrconfig.xml

    <str name="queryAnalyzerFieldType">text_general</str>
       field types. Text content will be indexed as "text_general" as
      <str name="fieldType">text_general</str>

# schema is from /usr/share/doc/dovecot/solr-schema.xml

dovecot-2.3.5.2 and the latest solr-8.0.0.

It seems XMLs do not match each other. How can I fix this problem?

Thanks.