We're not able to reproduce the problem on our end.
Could you try to :
- switch the "Use AJAX when possible for add to cart buttons" setting of the HikaShop configuration
- change the "checkout sef name" setting of the Hikashop configuration
Does that help ?
If that doesn't help, could you provide a backend and FTP access to the website along with a link to this thread via our contact form so that we could analyze the issue ?
As a quick fix, you can change the "After a product is added to the cart" setting in order to temporarily remove the popup.
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.