If you get the message that the midi ports are in use by another application, then the simplest thing to do is to close all running applications, then start GPO Studio first and then Overture. You shouldn\'t need any other applications running. Also don\'t run the midi inputs utility for GPO Studio, since it is intended for using GPO Studio with your sequencer on a second computer - definitely this won\'t be the situation you are in with Overture.
If you still get a message that ports are busy, than probably some midi application on your system didn\'t properly close the ports earlier when it exited. Reboot your system and you shouldn\'t have any problem with the message.