My friends and I, are unable to join each other in private worlds. (Not the public servers that are featured). They are running on version 1.2.0.20 on xbox, I have tried inviting them via Xbox live, They have tried inviting me, and it does not work. I have port-forwarded and I am on beta, so are they, they are "Unable to join world".

Is this a bug or is cross-play in private worlds not out.

Update: Windows 10 players can join Xbox one worlds only, Xbox one cannot join window 10 worlds.