Blizzard has issued an apology to Diablo III players affected by the game's technical issues, including the discovery of a game-breaking bug.
Posting on the Diablo III forums, Blizzard said that its preparations for the launch of the game "did not go far enough."
"As many of you are aware, technical issues occurring within hours after the game's launch led to players experiencing error messages and difficulty logging in. These issues cropped up again last night for the Americas and Europe servers. Despite very aggressive projections, our preparations for the launch of the game did not go far enough.
"To that end, we'd also like to say that we've been humbled by your enthusiasm--and we sincerely regret that your crusade to bring down the Lord of Terror was thwarted not by mobs of demons, but by mortal infrastructure."
Blizzard announced that it has been monitoring the game around the clock and said it has applied several optimizations to help the servers deal with the global rush. According to the publisher, all systems are now back online and "running relatively smoothly." The company said that it is also investigating a fix for a service issue linked to the achievement system, which saw achievements not being earned properly or not being saved between multiple log-ins.
As a result of the technical difficulties, Blizzard has decided to push back the target launch for Diablo III's real-money auction house, originally estimated for May 22. The company said it will post further information about this in the near future.
The publisher stated that it would continue to monitor global performance of the servers and will be taking further measures as needed, including maintenance to improve each region.