douglance

Add this code to your theme’s function.php file:

add_filter('mime_types', 'my_mimes');

	function my_mimes($mimes) {
	    // add your mime types
	    $mimes['epub'] = 'application/epub';
		$mimes['mobi'] = 'application/mobi';
	    return $mimes;
	}

I use Buddyboss too, and I have the same problem.