Hi,
Regarding the translation error message, it says that you need to first enter the text in the variant description itself before you enter the text in the description field of the translation popup. Did you do that and save the variant at least once before ?
If not, that would explain the error message as the system actually need to use the text from the variant description as key to match it with the translation text in the popup.
Now, what's strange is that I see that you only have French setup on your website (only the French flag appears on your first screenshot). So In that case, there is no need to add any translation since you can just let the system use the text from the description in the variant itself. So I'm thinking that you're having an issue with your HTML editor not displaying for the description of the variant when you edit the variant, and because of that, you thought that you had to use the translation flag to be able to enter the text, which then lead to the error message.
So if my theory is correct, your issue is actually with your HTML editor not loading properly.
In the HikaShop configuration, you'll find under the "advanced" tab a setting "Editor" where you can choose which editor plugin to use in the HikaShop interface. I would recommend to change it to "tinyMCE" the default one of Joomla and it might help. Or even try with "none" to get just a text area. That may help you better understand how the interface is normally supposed to work, when the editor doesn't mess with everything.
Regarding the images upload, I must say I've never seen that. So I'm not sure what's going on. Could you maybe provide a backend access and precise instructions to reproduce the issue so that we could look into it ?
If so, you can send that along with a link to this thread via our contact form:
www.hikashop.com/support/contact-us.html