If you have an existing Velocity installation, you can upgrade or update it instead of performing the new installation described in the Updating from v3.6 (or higher) to v3.8.5 section.
Upgrades versus Updates
In the past, moving an existing Velocity system to the next major release required an upgrade, which typically included some changes to the structure of the Velocity database. An upgrade was indicated by an increase in the major release number, such as from 3.5 to 3.6 or 3.7 to 3.8 or 3.8 to 3.8.1 or 3.8.1 to 3.8.2 or 3.8.3 or 3.8.4 or 3.8.5.
...
Existing Velocity users moving from 3.6 or 3.7 to 3.8/3.8.1/3.8.2/3.8.3/3.8.4/3.8.5 use the Velocity Update Wizard. This wizard simplifies the effort required to upgrade and uses smaller installation files than the Upgrade Wizards provided for previous Velocity versions.
Upgrade Paths
There are specific upgrade paths you can choose from. In the following diagram, locate your existing version of Velocity, then follow the best available upgrade path to Velocity 3.8.5:
...
If you are running any 3.6 release, you should update to the 3.7/3.8/3.8.1/3.8.2/3.8.3/3.8.4/3.8.5 release.
Starting with the Velocity 3.7 release, customers will need to obtain a software license when updating an existing system. Refer to section: Obtaining and Adding Velocity License.
Preparing to Upgrade
Before you start the upgrade process, you must perform these required tasks:
Back up your database before attempting any upgrade. Doing so enables you to return to an earlier working state if a mistake is made somewhere in the upgrade process.
Before updating to Velocity 3.8.5 from a Velocity 3.7 release, you must register your Velocity software and obtain the necessary license(s). See the Velocity Licensing topic for details.
Existing Velocity users moving from 3.6 or 3.7 to 3.8 or 3.8.1 or 3.8.2 or 3.8.3, or 3.8.4 or 3.8.5 use the Velocity Update Wizard. This wizard simplifies the effort required to upgrade and uses smaller installation files than the Upgrade Wizards provided for previous Velocity versions.
New installations of Velocity 3.8.5 provide you with the option to install the free Express edition of SQL Server 2019. Suppose this Express edition is not adequate for your needs. In that case, you must install a licensed edition of a supported version (2016, 2017, or 2019) of SQL Server before doing a new Server installation of Velocity 3.8.5.
If you already have SQL Server 2016, 2017, or 2019 installed on your server, the Velocity 3.8.5 Installer detects and uses your complete edition of SQL Server for the Velocity database.
Make sure the available Hard Disk free space is at least twice the size of your Velocity database. This requirement applies regardless of whether you have the Express edition of SQL Server or a licensed complete edition.
Make sure that you are logged in with an appropriate administrator account . You must be a Domain Administrator for a networked Domain account or a Local Administrator account for a stand-alone workstation installationor have administrator privileges and have permission to update the Velocity Database.