I have been building a site http://www.racingpigeon.com
The site includes a bbpress forum.

I found that there was peculiar things going on with the forum such as it could not be accessed from the back end. It can be viewed from the front end until someone logs in then it becomes blocked and returns 404. This happened first on the production site but was confirmed on a pilot installation also by deactivating and reactivating Ad King Pro. 1.9.9
bbPress 2.5.3

[@netweb Keymaster 10 years, 10 months ago]

There is a support topic for that in their support forums, hopefully an update Ad King Pro’ will come along soon that resolves the issue.

https://wordpress.org/support/topic/bbpress-30?replies=2