update: Ubisoft has released an official statement saying that they have identified the problem and are currently working on restoring everyone's characters, stressing that the characters aren't lost forever:
The issue was caused by a malfunctioning server that couldn’t synchronize character data correctly and corrupted them instead. The game client was unable to read this corrupted data, and simply assumed that the character didn’t exist. Once this has been identified, we were able to restore the server to its normal functions, thus ensuring that the issue will no longer occur for other players.Game development is a tricky thing. More often than not, developers will release patches post-release to fix some unintended behavior in the code. Sometimes, the introduction of a patch to the live code can bring with it entirely new, unintended bugs.
Many players playing the Xbox One version of Ubisoft Massive's MMO-lite cover shooter Tom Clancy's The Division have found a bug in the new patch, released yesterday, that went ahead and deleted their characters, effectively undoing all the work they have put into that character up to this point. The player who was the first to broach the subject on a Reddit thread, encountered this bug report that a login attempt resulting in a delta or mike error. After trying to log in again the player found that his character was conspicuously absent from the login page.
In the Reddit thread, a Ubisoft employee called on anyone who encountered this bug to send them their Xbox Live account name associated with the affected account, saying that the team will be looking into each and every character they have received. A community manager has said that they will be able to give those affected their characters back.
Yesterday's patch added a bunch of new things to The Division, like a tweaked crafting system, Dark Zone live events and an end-game incursion meant for players with an item level above 140 (this incursion, as it turns out, was completed by players a couple hours after it got added to the game). Read more about this patch here.
If you've been affected by this you can make a ticket by going here.