Earlier today, the Division servers went down for maintenance in order for the developers to apply a new patch to the game. However, the maintenance ended much earlier than expected, with the servers returning at around 12noon CET.
"Prior to deployment, it has been found that the patch was unsuccessful and has been delayed. As such, today's maintenance will finish early" Ubisoft have said in an official forum post. "This also means that the deployment of the Clear Sky Challenge Mode has been delayed for the time being as well."
The reason the maintenance ended early was because the patch went wrong somewhere along the lines, and has now been delayed. As a result, the new challenge mode entitled Clear Sky, has also been delayed.
As of right now, there is no ETA on when the update will actually be implemented, but at least there servers have opened up again so people can play the game.
Ubisoft did later tweet that a client fix for the "double UI" problem is going out now on Xbox One. So that's something. Hopefully they'll roll out all the patches and content soon across all platforms.