It may be that your virus definitions are out of date - find your Anti-Virus software, within this there will be an option to "update definitions". As we allow so many different types of AV Software it's not possible to detail the exact menu options of each one on this page. Generally AV software will allow you to right click a system tray icon and select Update Definitions or just Update (the system tray is usually next to your clock, showing a number of small icons for various software you have running).
Hover over each system tray icon and it will display which software it pertains to, so you can be sure you have the correct one.
Another potential solution is that you might have more than one Anti-Virus solution installed. vpn.fil.com cannot work with multiple versions or softwares, as this causes a conflict and hence an error message. Check your Add/Remove Programs list and make sure you just have the one software installed to manage this aspect of your security.