Hermod has been updated to use Spring Boot 2.x and Java 11. The deployment and configuration is NOT backward compatible, but the functionality is. Many configuration properties have been renamed or changed and manual update of the Hermod configuration file IS REQUIRED. For more information, see Upgrade Hermod from 2.x to 3.x.
If you are updating Hermod from version < 2.4.1 and are using Microsoft SQL Server you must alter the aliases table. There were also new indexes added in version 2.5.1. For more information, see the last sections of Upgrade Hermod.