Проблема Ошибка в заказах

всем привет. при переходе в заказы начала выводиться ошибка. помогите кто знает
вот такая ошибка в логе

2015-11-11 19:51:25 ERROR vmError: exeSortSearchListQuery Unknown column 'u.last_name' in 'field list' SQL=SELECT o.*, CONCAT_WS(' ',u.first_name,u.middle_name,u.last_name) AS order_name ,u.email as order_email,pm.payment_name AS payment_method FROM bbrxn_virtuemart_orders as o
LEFT JOIN bbrxn_virtuemart_order_userinfos as u
ON u.virtuemart_order_id = o.virtuemart_order_id AND u.address_type="BT"
LEFT JOIN bbrxn_virtuemart_paymentmethods_en_gb as pm
ON o.virtuemart_paymentmethod_id = pm.virtuemart_paymentmethod_id
WHERE ( u.virtuemart_user_id = 42 AND o.virtuemart_vendor_id = "1" )
order by o.modified_on DESC