Ubisoft has apologised to gamers for the fact that its servers went down over the weekend, saying it was attacked by a hacker.
The company's new DRM system failed yesterday. And because its authentication system requires players to be online at all times, even when playing a single-player game, gamers were unable to play Assassin's Creed II and Silent Hunter 5 on the PC.
At first the company reckoned that 'exceptional demand' was the cause of the problem.
"Clearly the extended downtime and lengthy login issues are unacceptable, particularly as I've been told these servers are constantly monitored," said a company representative on the Ubisoft forum.
"I'll do what I can to get more information on what the issue is here first thing tomorrow and push for a resolution and assurance this won't happen in the future."
Now, though, Ubisoft reckons it's been hacked.
"Apologies to anyone who couldn’t play ACII or SH5 yesterday. Servers were attacked which limited service from 2:30pm to 9pm Paris time," the company said today in a tweet.
It added, "95% of players were not affected, but a small group of players attempting to open a game session did receive denial of service errors."
Ubisoft's already come under fire for its new authentication system, intended to combat piracy, with gamers pointing out that for many people the requirement to be online at all times means extra cost.