Windows 7 and macOS 10.6 Snow Leopard are the last OS that are tested to support updating X-Rack.
It is not possible to update with macOS 10.7 or higher.
Windows 8, 10, and later are untested.
On a Mac, Bootcamp running Windows 7 or XP should also work. Windows can run for a trial period without authorization.
1.4/9 is the latest version, released 2011.
See owner's manual section 4 Show Version to check the software running on your X-Rack.