Hi,
The issue is that you have a problem with your newsletter module. It is adding invalid javascript code to the page and this breaks the initialization of the javascript on the page, including the javascript of HikaShop.
If you disable that newsletter extension, it should work fine. I would recommend to contact your newsletter extension provider so that they can analyze the issue with the javascript code they're adding to the page and fix it.
Alternatively, you can use another newsletter extension like AcyMailing which doesn't have that issue.