Activations not always available on a single computer
Possible cause and solution:
The activation is locked to a virtual network adapter, such as a virtual private network (VPN) or virtual machine or is locked to a device that is currently not available, such as a network adapter, docking station, or a network adapter on a laptop that automatically powers down when not in use.
Rehost the activation. Get a new activation and lock it to the bindings of devices that are always available, such as hard disk serial numbers or Ethernet network adapters.