[@delayedinsanity Member 16 years, 3 months ago]

It works great if you’re running your forums as a sub-directory of your WP install, but it breaks as is if you’re trying to run your forums under a sub-domain.

Anybody who happens to know a work-around, feel free to check out: https://bbpress.org/forums/topic/bbpress-in-a-subdomain-on-a-wpmu-install