If you are on Active Directory and your VPN Software does not set the DNS servers to your local Domain Controllers, you may encounter the following error:
The system has detected a possible attempt to compromise security. Please ensure you can contact the server that authenticated you.
This appears to be some sort of problem with cached credentials and the inability to contact the DC even though you are on its subnet. If at all possible, have your administrator configure your VPN software to set your Primary DNS to the IP of the DC on your network. If that can’t be done, adding an IP and hostname entry for your DC to LMHOSTS should work. For example
192.168.0.1 CorpDCserver #DOM:corpdomain.com