Update: Microsoft resolved all issues and the service is now operating as usual.
Microsoft has confirmed that Xbox services are currently suffering from a major outage. Because of it, users cannot sign into their Xbox accounts on consoles (all the way down to Xbox 360), PC, mobile devices and the web. In addition, the outage took down social features, such as joining parties, receiving invites, staying in a party after joining it, etc.
Cloud gaming and remote play are also flagged as "Major outage." Microsoft confirmed that gamers are being disconnected from games or unable to access them altogether. Other parts of Xbox services, such as the store, online safety, subscriptions, and multiplayer, continue operating as usual.
Interestingly, Sony"s PlayStation Network also experienced a significant outage in the last 24 hours, and it seems that Xbox Live and its users are the next to suffer.
The issue was first reported about an hour ago, and Microsoft has now confirmed the outage and is seeking a resolution. You can check Xbox Status on the official website. We will update this post once the problems are resolved.