==== Server Logs (CMD console) ====
[12:45:40][INFO] : Starting DMPServer 5ba31d4, protocol 22

[...Trimmed...]

[13:17:48][INFO] : Connection error for client CP44, endpoint 43.[IP scrubbed]:50944 error: 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.BeginReceive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, AsyncCallback callback, Object state)
at System.Net.Sockets.NetworkStream.BeginRead(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.BeginRead(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state)
at DarkMultiPlayerServer.ClientHandler.ReceiveCallback(IAsyncResult ar)
/list
[13:19:58][INFO] : Command input: /list
[13:19:58][INFO] : Unknown command: list
[13:20:03][INFO] : Command input: /listclients
[13:20:03][INFO] : No clients connected

==== Client Logs (ksp.log) ====
[LOG 13:17:41.090] [8584.973] DarkMultiPlayer: Found reference to asteroid spawner
[LOG 13:17:41.091] [8584.974] DarkMultiPlayer: Skipping the removal of vessel 6ba45854-9d08-4ec2-ac29-605a1ed8025f, name: Ast. KIU-553, update lock owned by another player.
[LOG 13:17:46.701] [8590.584] DarkMultiPlayer: Sending disconnect message, reason: Quit
[LOG 13:17:46.701] [8590.584] DarkMultiPlayer: Disconnecting, reason: Connection ended: Quit
[LOG 13:17:46.702] [8590.584] DarkMultiPlayer: Disconnected

Client returned to main menu and displayed "Connection ended: Quit" as expected.

Fixed via f6e1576