I can't connect to my friend in Minecraft

As soon as the project is my friend's world in the friends menu, failing to enter the world and the following error "unable to connect to the world" appears. Played on the same version and my Xbox Live multiplayer settings are available for adults, so I don't see a simple reason for not being able to connect to the world. Note: c enter multiplayer servers but fail to enter a world full of friends. I ask for help.