We've changed the location of our contributor's chat server. It is now located at chat.hackerexperience.com. A new account must be created.
This change is part of an effort to overhaul the way we deal with contributions and the community. This post describes how the new Hacker Experience Community works, as well as the new contribution process.
Another reason for changing chat servers (and thus requiring a new account be created) is for security. We want the community chat to 1) be hosted outside the game intranet and 2) be hosted on a different server than our internal chat, which may contain sensitive information/files.

Sorry for the inconvenience, hope you understand :)