BTW, when I say "I tried configuring VirtualBox to use a 'Bridged Adaptor' and 'NAT', separately. Testing with each failed both times.", I meant that FortiClient failed to connect in the Windows guest.
BTW, when I say "I tried configuring VirtualBox to use a 'Bridged Adaptor' and 'NAT', separately. Testing with each failed both times.", I meant that FortiClient failed to connect in the Windows guest.