According to the developers BBPress is a bit behind handling this integration and it’s assumed at some point it will. That said, I got around this irksome problem by creating my own little plugin. (Actually I maintain a custom-functions plugin for just this type of thing). It’s pretty simple really, just create a new file in your mu-plugins directory and this code to it.
//--------------------------------------------------------//
//---Hook-------------------------------------------------//
//--------------------------------------------------------//
add_action('wpmu_activate_blog', 'add_new_user_to_mainblog', 10,2);
add_action('wpmu_new_blog', 'add_new_user_to_mainblog', 10,2);
//--------------------------------------------------------//
//---Functions---------------------------------------------//
//--------------------------------------------------------//
function add_new_user_to_mainblog($blog_id, $user_id) {
add_user_to_blog( '1', $user_id, 'subscriber' );
}
Basically all this is doing is using the hook wpmu_activate_blog to trigger the function add_user_to_blog. WPMU also has this habit (not sure why exactly) of removing an existing user from the main blog when they reated another new blog. Not a huge deal again but problematic if they haven’t logged into BBPress already. So the second add_action triggers on wpmu_new_blog to add the user back.
Simple as that. Of course, this doesn’t handle getting any existing users set as subscribers so you’ll have to do those manually or write a script to do it, but any new users should get added just fine.
