Fatal Exception while using secured connection

I am using SECURED CONNECTION with websocket.
On Startup of websocket server I am getting following error :

9/8/2016 10:34:45 AM|Fatal|QueueUserWorkItemCallback.WaitCallback_Context|System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Net.Security.SslStream.AuthenticateAsServer(X509Certificate serverCertificate, Boolean clientCertificateRequired, SslProtocols enabledSslProtocols, Boolean checkCertificateRevocation)
at WebSocketSharp.Net.WebSockets.TcpListenerWebSocketContext..ctor(TcpClient tcpClient, String protocol, Boolean secure, ServerSslConfiguration sslConfig, Logger logger)
at WebSocketSharp.Ext.GetWebSocketContext(TcpClient tcpClient, String protocol, Boolean secure, ServerSslConfiguration sslConfig, Logger logger)
at WebSocketSharp.Server.WebSocketServer.<>c__DisplayClass6.b__5(Object state)

Note : Continuously I am getting this error.

Start at WebSocketServer.receiveRequest and follow the stack through WebSocketSharp.Ext.GetWebSocketContext, TcpListenerWebSocketContext, and SslStream.AuthenticateAsServer. Reproduce the secured WebSocket startup failure and inspect the server SSL configuration and connection behavior. Done means identifying a reproducible cause and documenting or implementing a verified fix.