Xbox Live is down, preventing sign-in for some users

[Windows Central]

Hopefully Microsoft is able to fix the problem soon.
Many Xbox players trying to connect to their Xbox network (formerly known as Xbox Live) profiles are currently experiencing issues signing in, indicating that Microsoft's systems are going through a rough patch. It doesn't appear that the problem is preventing people from playing online if they're already signed in, but many players who are trying to log in on Xbox Live are not able to access their accounts.

Full story from the WindowsCentral blog...