I can't get into my friend's world

Hi, I'm trying to play with a friend of mine for a long time, and every time we try to get into each other's world this error (image) I really don't know how to solve this problem, (she and I already is a friend in xbox) we bought the game together so we can play and we are not able to, her world appears to enter and when I press and hope to load the error of the image, we tried more than 10x yesterday .. and if you can solve i appreciate it