To play on Minecraft Realms you need two privacy settings to be enabled (Join multiplayer and create and join clubs) . It isn’t very obvious and sometimes error messages aren’t very helpful. There are two ways to update your settings, on your Xbox or on Xbox.com. Here I will show you how to change your privacy settings on your Xbox.
Step 1: Press the Guide button and go to Settings
Step 2: Click on “Online safety and family”
Step 3: Click Privacy & online safety
Step 4: Click Xbox Live privacy
Step 5: Click on Friends & clubs and set “You can create and join clubs” to Allow
Step 6: Click on Communication & multiplayer and set “You can join multiplayer games” to Allow