This problem may occur if the network settings were specified incorrectly or ports are blocked.
1. Check the Network Configuration.
2. Press <Right Shift> on the keyboard connected to RPN Player to open the window with the network settings.
3. If all the network settings are correct, check the firewall settings. The ports 20, 21, 80 and 2222 should not be blocked by any anti-virus or firewall application.