by 17-BIT Borut » Tue Feb 19, 2013 5:14 am
So this can happen in a couple instances:
On Xbox 360, you need an Xbox Live Gold membership to play online. This is Microsoft's policy. (However on Windows Phone and Windows 8 you can play online using the Skulls anywhere mode with just a silver profile).
Or, on any platform, this will happen if you profile has had Xbox Live multiplayer privileges turned off (that's one of the parental controls) - however this would still allow you to post to leaderboards.