Make sure that you have installed Microsoft .NET Framework 4 and the UAC (User Account Control) is disabled. If it is not disabled, go to Start > Control Panel > User Accounts and Family Safety > User Accounts > Change User Account Control settings, drag the slider down and click OK. After that, go to Start, type Windows Defender and open the utility. Navigate to Tools > Options > Administrator, un-check the Use this program box and try to run the game using Administrator rights. Also, type Allow a program through Windows Firewall in the Search programs and files field, open the utility and check the box next to PlayRF USA. If you can't find the game in the Allowed programs and features window, press the Allow another program button, navigate to the installation directory and open the executable file. Also, make sure that your antivirus program doesn't block the connection. If the game doesn't work, download and install the latest version from the official web page.