Pasted

add_action( 'woocommerce_order_status_on-hold',  'custom_call_groupbuy_order' );
function custom_call_groupbuy_order($order_id){
    global $wc_groupbuy;
    $var = new wc_groupbuy_Admin($wc_groupbuy->get_wc_groupbuy(), $wc_groupbuy->get_version(), $wc_groupbuy->get_path(), $wc_groupbuy->get_plugin_basename());
    $var->groupbuy_order($order_id);
}