This issue might be connected within your internet connection. The server is working fine as everyone can connect to it and I am seeing PK players not getting this error. (I have ask some PK players).
The first thing you might want to try is restarting/resetting your internet connection and if your network still getting this problem, Check your internet speed and if doesn't meet the requirement contact your internet provider. Well, if this isn't connected to your internet connection. Try the basic steps, Re-install MTA.