Reasons why you are disconnected from server!
3. If you ping sever or use any 3rd party programs, your IP address can be banned by server anti-ddos system. It unblocks in 6hours automatically. Try to use some VPN in this case.
1. Check if server is online, go to homepage and check server status, if website shows ONLINE, and player count, it means server is online.
2. To play the game and to connect to server players must connect to server port 44405. Some work places/schools/e-caffes have ports blocked, and you wont able to connect to server from that place! Contact your system/internet provider.