My friend and I cannot join each others' worlds. We have tried both via LAN and also through the XBOX friend option.
We used to join each others' worlds all the time, and suddenly it stopped working as soon as Realms came out. (We are able to play on the same Realm just fine. The only issue is specifically joining each other on our own worlds.)
We always are able to see each others' worlds but when we try to join each we get different error messages depending on the day. Most recently the error is simply "You have disconnected".