That plugin is custom to WordPress.com, so it’s not really for wide usage yet. But I did find these notes for WPMU usage: I needed to do two things to make it work: On line 131 change is_int() to is_numeric(): if ( is_numeric( $blog_id ) ) { switch_to_blog( $blog_id ); $current_plugins = apply_filters( ‘active_plugins’, get_option(…