Hi,
I will need more information to better understand the situation as I don't see what file I could give you which would help you.
I checked your website with the URL you provided, but I didn't get any 404 error on the different links of your shop I tried in both languages. So I'm not sure what is wrong.
Are you using Falang or not for translations ?
Could you provide a URL of a page with a link resulting in a 404 error and tell us which link on that page is problematic ?
Could you also provide screenshots of the product (or category if the problem is on a category) settings so that we can better understand what you did ?
Now, checking your website, I can see that you have a build of HikaShop 4.4.1 from early march. Since then, we've got a feedback about issues with language switching on multilingual websites here:
www.hikashop.com/forum/10-translation/90...ranslation-bugs.html
Following that, we've added a big patch so that it works properly. So I would recommend to download again the install package of the 4.4.1 on our website and install it again on yours to get that patch. It might help your situation.