When the Content Server starts the first time after upgrading, it will automatically remove the no longer needed foreign key constraint fk_WfV_group on column groupValue_0 of table WfVariables for existing Oracle, MariaDB and MySQL databases.

Note, that it is not possible to start a Content Server of a previous release on the database after the new Content Server has adapted the database tables. This also the case for the otherwise unchanged database PostgreSQL. You should always make a backup of the Content Server database before upgrading. This is even more important for this change.

(CMS-18857)