We will need to check your license key state so you need to connect to internet connection when you have this error but you can disable internet again after doing the check.
I discover through Damien’s answer that audirvana’s platform must be connected to internet, for the purpose of checking the user is entitled to use Audirvana.
This sounds fair to me, but it does not solve the problem you are facing at work to connect your PC to the internet.
Have you considered using your own smart phone as a shared WiFi access point on which to tether your PC while using Audirvana?
I suppose that the data used is very small and should not bust your contractual data entitlement.