Virtual port are not supported by the Windows MultiMedia API

On windows it's not possible to create virtual ports with o-s-c as you would with loopMidi but it is possible to connect to these ports. One known limitation found recently is that you can't connect to a midi port if another software is already connected to this port.

The issue is that I'm not able to route my MIDI in Windows10 either.

More details on that may help too;)