Hi,
From what I can see the HikaShop views have been heavily customized on your website.
And that's not an error we ever got reported, so I think these errors comes from the customization done. So it's hard to say what to do precisely.
I would recommend to check the folders in templates/YOUR_TEMPLATE/html/com_hikashop/ via FTP.
There, you should have a product and a category folders which contain the view overrides for the categories and the products display pages. So you could try renaming the files in these folders one by one to identify which ones are creating the problem with the URL of the products / categories and then once you do, keep them renamed and potentially redo the overrides if you lost some customization.