ORelio/Minecraft-Console-Client — pull request #56 by RuZniki (2014-12-17 01:59:38+00:00)
Title: Convert ServerPort from short to ushort

So this is problem: https://github.com/ORelio/Minecraft-Console-Client/issues/55
This is my patch. I'm not familiar with .NET so please test it.
Also maybe it's good idea to do additional check for port value, and provide user more information if he accidentally use wrong port.