Activation is required when tried to create virtual machine by using Windows OS's public template.
When Activation is requested, please check route settings of guest OS on virtual server.
In case of configuring non vfirewall address to default gateway, please configure new routings on guest OS.
After new routings are configured and connected to license server is up, guest OS of virtual server automatically conducts Activation.
Please see below link for how to change default gateway via vFirewall.
"In Windows Server 2012, I would like to change the default gateway used by the vFirewall (or some other integrated network appliance). If need to add new static routing information, what sort of information exactly should I add?"