We guarantee that our games will never contain a virus, and that it's completely safe to play our games.
It could be that your security software, such as your virusscanner or firewall, has done an automatic update on your computer. Some of such updates wrongfully identify safe files as dangerous.
When our server makes contact with your computer to verify your account, your security software may interrupt this connection, which causes our server to believe that you have no Internet connection and therefore the game won't be able to start.
We guarantee that there are no harmful files in our games, so it's safe for you to briefly turn off your security software during the login process. You can turn it on again after you've logged in to the game. You can also inform the supplier of your security software about the error in their software.