product not found after enable remove products ID

-- url of the page with the problem -- : air-learning.nl/cursus-aanbod/product/7-facetten-seichim.html
-- HikaShop version -- : 2.3.0
-- Joomla version -- : 3.2.3
-- PHP version -- : 5.4.25
-- Browser(s) name and version -- : all

When i enable the option Remove products and categories id in URLs in the configuration of Hikashop all products starting with a number i get the message "Product not found" when i disable this option the product is visible again.

This issue is only occur when this SEO option is enabled for products those starting with a number (0-9) how can i solve this?

That's normal since the number at the beginning is interpreted as being the id of the product.
You'll have to fill the "alias" field of these products with the text you want in the URL for these products without the number at the beginning.