Update: Humanity restored—multiplayer is alive once more, without a word of explanation.
The problem extends to all multiplayer functionality: invasions, cooperation and even messages between worlds. Despite two sequels, Dark Souls still has a bustling community and the long silence is driving them mad.
The outage corresponds with a modification made to Dark Souls' Steam config files. Some players are speculating that it's to free up resources for Dark Souls 3 multiplayer, others suspect a conspiracy to drive more players to the new release, but Bandai Namco is silent on the issue. The only official acknowledgement comes via community manager J. Kartje, but that was five days ago.
