Ever since the release of Microsoft's new dashboard the other week, some unlucky users have been unable to get their consoles back online, something the company is promising to "resolve ... as soon as possible".
"We have recently identified an Xbox Live profile data error that results in Error Code '801540B7' for a small number of Xbox Live members", an Xbox representative told Joystiq. "The error instructs users to attempt to re-download their Xbox Live profile and directs them to customer service support for further assistance. We apologize for the inconvenience this has caused to our loyal Xbox Live members and are working to resolve the issue as soon as possible."
The consoles are being kept offline by an inability to sign their profiles into Xbox Live, which means they're not just being kept out of multiplayer games, they're being locked out of some purchased content as well.
It's not the first problem to pop up with the new dashboard; people who watch a lot of video content have found that the console's capabilities in that regard have gone downhill as well.