It is a pleasure to inform that the new version of Lucene library and Solr search server has been released. It is another release from the 6.x branch and it is numbered 6.4.2. Release fixes a few bugs found in the 6.4 and 6.4.1 versions of Lucene and Solr.
Apache Lucene library 6.4.2 can be downloaded from: http://www.apache.org/dyn/closer.cgi/lucene/java/. If you want to download Solr search server 6.4.2 go to http://www.apache.org/dyn/closer.cgi/lucene/solr/.