Xbox Live is currently down on Xbox One. It’s unclear whaat’s causing the issue but currently people are having trouble logging in to play games, accessing online services and playing games against other people online.
There’s no estimated time for when the service will be fixed, but it’s nearing an hour now since services have been affected.
The Xbox support Twitter has Tweeted that the teams are investigating the issue and an update will be provide when it’s available.
We've got the proper teams investigating sign-in issues across Xbox One consoles & our website. We'll provide more info when we have it!
— Xbox Support (@XboxSupport) October 10, 2017
The Xbox support website also suggests that there are issues across the entire Xbox online service.