I’ve just tried registering Runtime V2 with the key we have on record as yours and it worked OK.
Could you please email the key you are using to email@example.com, and a copy of the configuration information from a machine where you can’t register the software. You can access the configuration information from the main GroupWise menu: Help | About Formativ. When the about box appears, select the configuration tab. Press the ‘copy to clipboard’ button, then paste the contents of the clipboard into a message to support.