Are you integrated with WordPress?
What version bbPress did you install, and WordPress too if you did integrate?
Any plugins? What theme are you using?
Language other than English?
When in doubt, post a link to your forum.
That error sounds similar to this one:
https://bbpress.org/forums/topic/who-can-shed-some-light-here
Are you using any of the plugins mentioned in that post? Might be worth disabling them temporarily, and seeing if that impacts the error…
Are you integrated with WordPress?
What version bbPress did you install, and WordPress too if you did integrate?
bbpress v1.0, WordPress v2.8.6
Any plugins? What theme are you using?
I did have some but disabled them all.
Language other than English?
No, just English
When in doubt, post a link to your forum.
http://www.highlysedated.com/bbpress
I can register from WordPress but whenever i try to register from bbpress i get that error message.
I registered just fine with bbPress. You will see my registration there.
I registered just fine with bbPress too.