You will receive that error if your appliance is not running version 19-2.
Be sure to run update50 first, as the spec says.:
Even if you just downloaded the appliance, ensure that it’s completely up-to-date by opening a terminal window, as via Menu > Programming > Terminal, typing
update50
and then hitting Enter on your keyboard. So long as your computer (and, thus, the appliance) has Internet access, the appliance should proceed to download and install any available updates.