UDP error in FPS demo with smartfox

I have downloaded FPS Demo and trying to run it with my smartfox server which is running live on dedicated server. When I run this project then connection is successfull but its giving an error when do login, I debug the code and found error in below line

 smartFox.InitUDP(serverName, serverPort);

Errors are :-

Login ok

[SFS DEBUG] UDPSocketLayer: Error reading data from socket: An existing connection was forcibly closed by the remote host. [SFS DEBUG] Unexpected UDP I/O Error. Error reading data from socket: An existing connection was forcibly closed by the remote host. [ConnectionReset]

[SFS DEBUG] [ BB-Send ]: 0d6a5429fc346a95103ea3c9259e86cc|poll|null

[SFS DEBUG] UDP Init Attempt: 2

[SFS DEBUG] UDPSocketLayer: Error reading data from socket: An existing connection was forcibly closed by the remote host. [SFS DEBUG] Unexpected UDP I/O Error. Error reading data from socket: An existing connection was forcibly closed by the remote host. [ConnectionReset]

[SFS DEBUG] UDP Init Attempt: 3

UDP error:

[SFS DEBUG] [ BB-Receive ]: poll|null

[SFS DEBUG] [ BB-Send ]: 0d6a5429fc346a95103ea3c9259e86cc|poll|null

Please let me know what I am doing wrong, is there any setting on the smartfox server whic I missed? Your suggestions are most welcome :)

Note : when I remove the UDP things from the code then it is working fine, but its lagging too much.