When the PhoneBox server is registered it ties your license to the PhoneBox server's primary Network card (NIC).

Invalid license

The can be cause by installing PhoneBox on a new server using it's existing license or by modifying the network card setup (New card, VPN, virtual adapters etc).

A new server will need a new license, please contact

If a new card, physical or virtual has been added, it may be set to the primary. To change the existing card back to primary please modify the Advanced Settings in Control Panel > Network and Internet > Network Connections.