Error An element with the same alias already exists Error Saving

-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.6.4
-- Error-message(debug-mod must be tuned on) -- : Error
Error
An element with the same alias already exists
Error Saving
Error Saving

Hello
After updating my hikashop I can not save products with variants. (I dont have this problem with saving products with no variants).

Error
An element with the same alias already exists
Error Saving

Hi,

www.hikashop.com/forum/product-category-...n-version-2-6-4.html
www.hikashop.com/forum/product-category-...ame-alias-error.html
www.hikashop.com/forum/product-category-...ias-already-exi.html

Regards,