In order to solve the connection error, go to Start > Control Panel > System and Security > Windows Firewall > Allow a program through Windows Firewall and check the box next to the utility. If you can't find the application in the Allowed programs and features window, press the Allow another program button, navigate to the installation directory, select the executable file and press Add.
After that, from the Advanced Settings select Inbound Rules > New Rule. Check the Port box, click Next, select All local Ports and follow the self-explained steps. Also, make sure that your security program doesn't block the connection. If it still doesn't work it is possible that the VoiceForMe servers to be temporarily down or under maintenance. In this case you will need to wait. Also, as an alternative, you can use Camfrog Video Chat software. It is free of charge, easy to use and has the same main features like VoiceForMe.