BuddyPress.org

I also saw this about multisite installs in the thread you posted:

“On multisite configurations, the post types that are registered on any sub-site will need to be registered on the root site in order to be listed in the Activity dropdown filters. That’s the case for the post and page post types”

The site I’m trying to create a custom post type for is a subsite. I assume the Page Post Type is registered for the root install, so this shouldn’t be causing the problem right?