Hello Patrick,
If you're only having "notice" and no warning messages it won't affect your shop.
Note that when your shop is in production mode you should :
- Disable the Joomla debug mode ("Administration->Global configuration->System->Debug System/Language")
- Set the "error reporting" option of the Joomla configuration to "none"
We just fixed it on our end, so you won't have that error message anymore with last Hikashop versions (that you can download through our website).
We wish you a nice day !
Kind regards,
Mohamed Thelji.