[chrishajer]

MarcoZ: that is perfectly fine as you are describing it. WordPress in the root of the domain, bbPress in a folder. You do create a directory called forum and copy the files there.

If you are not including WordPress in your bbPress, then you won’t need this plugin to correct the WordPress 404 errors:

https://bbpress.org/forums/topic/bbpress-wordpress-mu-or-not-leads-to-404-errors-but-pages-still-load#post-13156

Try your installation without that plugin first.