Unable to search emails in Roundcube after Dovecot Solr upgrades from version 8 to 9.

Symptoms

When entering a search in Roundcube Webmail, an error appears at the bottom right of the screen indicating that an error occurred.

#  Internal Server Error

The maillog file returns an error about the FTS.

• Maillog file is located at path: /var/log/maillog

  CONFIG_TEXT: Error: fts_solr: Lookup failed: 500 Server Error

The Dovecot Solr log returns an error about needing a reindex.

• Solr log is located at path: /home/cpanelsolr/server/logs/solr.log

  CONFIG_TEXT: o.a.s.s.HttpSolrCall 500 Exception => java.lang.Illega lStateException: unexpected docvalues type NONE for field 'uid' (expected=NUMERIC). Re-index with correct docvalues type.        at org.apache.lucene.index.DocValues.checkField(DocValues.java:218)

Cause

cPanel recently upgraded Dovecot Solr from version 8 to 9. The version change includes a schema change to some values. Due to the schema change, the field 'uid' values are returned as 'NONE'. Dovecot Solr recommends rebuilding the index during a version change, as the schema could've changed.

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-48198. Follow this article to receive an email notification when a solution is published in the product. 

Resolution

Rebuild the index as the issue will affect multiple users.

# /usr/local/cpanel/3rdparty/scripts/cpanel_dovecot_solr_rebuild_index