Why does my xbox 360 gamer profile says not capable?

Im tryinqq to play row 2 online and it keeps saying that my gamer profice is not capbale. Can anyone assit me %26amp; add me Kingkong ZaWhy does my xbox 360 gamer profile says not capable?If you have mods on your xbox or have switched game saves, you need to rehash and resign the modified contents. otherwise, it will tell you that.