Custom fields filters not working anymore (1604)

-- HikaShop version -- : 2.4.0
-- Joomla version -- : 3.4.0
-- PHP version -- : 5.4.17
-- Error-message(debug-mod must be tuned on) -- : Erreur: 1064
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'OR b.certification_en LIKE 'EN A,%' OR b.certification_en LIKE '%,EN A' OR b.cer' at line 1 SQL=SELECT DISTINCT b.* , case when b.price_currency_id IS NULL then 0 when b.price_currency_id = '1' and b.product_tax_id = '11' then b.price_value+b.price_value*0.2 when b.price_currency_id = '1' and b.product_tax_id = '35' then b.price_value+b.price_value*0 when b.price_currency_id = '1' and b.product_tax_id = '36' then b.price_value+b.price_value*0.055 when b.price_currency_id = '1' and b.product_tax_id NOT IN ('11','35','36') then b.price_value end as product_price_normalized FROM ls19i_hikashop_product_category AS a LEFT JOIN (SELECT * FROM ls19i_hikashop_product AS product3 LEFT JOIN ls19i_hikashop_price AS price3 ON product3.product_id=price3.price_product_id WHERE (price3.price_access = 'all' OR price3.price_access LIKE '%,1,%' OR ISNULL(price3.price_access)) AND product3.product_type='main' GROUP BY product3.product_id ORDER BY price3.price_min_quantity ASC) AS b ON a.product_id=b.product_id INNER JOIN ls19i_hikashop_category AS Marque2 ON Marque2.category_id=b.product_manufacturer_id AND b.product_manufacturer_id IN (28) WHERE b.product_published=1 AND b.product_type = 'main' AND a.category_id IN (15) AND b.product_quantity!=0 AND (b.product_access = 'all' OR b.product_access LIKE '%,1,%') AND (b.certification_en = 'EN A' OR OR b.certification_en LIKE 'EN A,%' OR b.certification_en LIKE '%,EN A' OR b.certification_en LIKE '%,EN A,%') ORDER BY product_price_normalized*1 DESC LIMIT 0, 20

Hi!

I have three filters on this page ( www.parapente-normandie.com/shop/categorie/voiles ), and the first one ("certification") is not working anymore, I get a 1604 error when I use it.
It used to work, and I guess it's not working after an update. What's wrong?
Thank you