Microsoft is working through a n issue right now that is preventing Xbox One consoles from signing into Xbox Live. Looks like it has been going on now for about the last 45 minutes, which if you look back at the Xbox Support Twitter feed, seems to be an ongoing issue from Oct 24th to today. If my count is correct, this is the 7th issue to spring up since then, mostly impacting sign in and download/purchasing. Hopefully they can get this issue corrected quickly, and figure out what underlying problems have been going on for the last week. I think there is a B.E.T.A. supposed to start in a couple hours that may have people upset if they cannot get in.