If you needed yet another reason to avoid Ubisoft games completely, they have just provided one. Apparently they are moving some of their services to new servers, and during that time, certain games will not function. At all. Even if you only want to play single-player games. That's because those games won't run unless they can access those Ubisoft servers. Behold the supreme idiocy of DRM.
They haven't even bothered to estimate the duration of the outage, so all you can do is keep trying until your game finally starts working again. So lame.
As if that's not bad enough, many in the tech industry (including myself) are scratching their heads, wondering why moving a critical service to new server hardware would be planned to involve more than a few seconds of downtime. This is not rocket science: get the new hardware up and running, flip the switch, then when everything looks okay, pull down the old servers.
The details are in this Ubisoft announcement:
http://static2.cdn.ubi.com/transition/details/