Make sure you don’t have more than 100 Xbox Live friends. This error might occur when you have more than Xbox Live 100 friends (including pending friend requests).
If you get this error and have more than 100 Xbox Live friends, delete friends until you have 100 or fewer. For more information about managing your Xbox Live friends, see Find friends and connect on Xbox Live.
If you’re still experiencing the problem, contact Xbox Support by clicking the “Contact us” link at the bottom of this page.