Hi,
That error message on your page is displayed by HikaShop's routing because it doesn't know what to do with it.
I'm not sure why it does this. I would need to check the structure of your menu items, the SEF settings of your HikaShop and the settings of your categories to be able to understand what's going on.
However, an easy solution would probably be to deactivate the "remove category and product ids from URLs" setting of the HikaShop configuration as it is by default.
The id in the URL helps the routing find the elements when a page is accessed. Without it, the routing system tries to find the elements based on their alias and if the alias is not provided or there is an issue with the translation system for the alias, it can lead to 404 errors.
Alternatively, you could check the "Support translated aliases in URLs" setting. Because if you've translated your aliases, you have to activate that setting so that the routing system can match the alias.
