I have the exact same problem right now. What server are you playing? check your task manager and see if there is a process running for the server.
Edit: After someone helped me, I was able to conclude that the korean patcher is to blame. Are you using sakray or KRO? If you are using sakray, delete it and download KRO only. I am not sure where to find it, but you should try downloading the offical korean game, then the server you need. Patch everything and try again.