THANK YOU! It worked!
If you can join others they should be able to pull you up by gamer tag and if a friend should be able to join you. I'm on Xbox and that is how I have joined friends worlds when it was not giving the invite screen in game. Wife also once had our three player world kick me and a friend when she went back in it would not let us join as some how it changed to a offline world. She just needed to change it back to online before starting again.I can play offline but it wont let me invite to my world, I can even join others.