Let me start by saying I own the game on 3 platforms, under the same MS Account. I own the game on Windows 10, Windows Mobile 10, and Xbox One. While I am hosting the server, xbox live game, from my Xbox One S (Beta Preview) I cannot connect both of my other licenses to the same world at the same time.

I was able to play from both my Window 10 copy or Windows Mobile 10 copy alongside of my Xbox, but all 3 could not occupy the same world.

The error message received upon trying to join was something among you were not authorized/invited to join the server at the time and then it would kick me to the main screen after. If I own 3 copies of the game, I should be able to have them all access the world simultaneously.