Error coupon

-- url of the page with the problem -- : cfiscuola.it
-- HikaShop version -- : 2.6.0
-- Joomla version -- : 3.4

Good morning, I upgraded to the new version of hika, now I have a problem on the coupon. I have not changed anything but the couppn now work poorly. Apply the discount set for 2 also produced a product only cart. As Picture


This is the setting that worked correctly before the upgrade.
What happened? What should I change?

Hi,

I'm not able to look at your issue as I'm not able to pass the registration screen. Could you provide a test account so that we can look at the issue ?