When installing or updating to Xinet 2021.5, Solr DB is deleted and the following warning message is displayed:
WARNING: Deleting Solr database. You will have to recreate it after this upgrade is finished.
2021.3 version of the Xinet Server comes packaged with Solr version 6.2.1 while Server version 2021.5 comes packaged with Solr version 8.5.1. As a result, the Solr database versions are incompatible and thus the installer must remove the existing Solr database in order to upgrade Solr to the new version. This is the intended behavior of the software. In addition, keep in mind that Solr configuration, including indexes, will not be retained once the database is removed.