One license key can only be used to activate a single machine. Have you applied the license key on another machine already? Or have you changed your network hardware? Please shutdown the backup service on the first server that you have this license key installed. After you have done this, please contact us at support@vaultusa.com and kindly provide us with your "License Name" and "License Key", we will update the license server to allow your key to be used again.

However, if you haven’t changed your hardware and are still getting this error, please check whether you have any installed software that would create virtual MAC address in the system, e.g. VPN software. If yes, please disable them, notify us to update your license, and update your [Software License] page again.