Hello,
In your template does not work function Display modal popup upon 'Add to cart' Virtuemart. Clear conflict of scripts.
example: webuzor.com/ru/katalog/kostyumy/sportivnyj-kostyum-gucci-detail
When changing the template on beez2 on the same site it is perfectly functioning. Please take steps to resolve the conflict.

Hi serg serg,

Your site is conflicted js , we fixed your issue. Please check your site again!

Thanks!