Upgrading in Horde 6 You can either upgrade an app or library and its dependency tree or the whole Horde installation. Upgrading the whole tree to latest Horde 6 This will honor any version constraints you have applied and any internal dependency constraints. composer update Upgrading a specific package composer update horde/rdo The installer will notify you of any conflicts preventing the upgrade Running schema upgrades after a software update You need to run this command to upgrade the database schema after an update vendor/bin/horde-db-migrate up