hi
ask about masternode
"Port 9999 must be open.", what is mean ? how to know is open ? to configure open
thanks
google "portchecker"
first result should be portchecker.co
type 9999 in the website and check
if its closed you need to open it by access your router. setup a port forwarding rule for the external and internal port 9999 for the ip address of the machine you want to use for FORCE