Hi,
For sure, HikaShop add that message in the Joomla system message queue ; but the display is not made by HikaShop, like Nicolas explained you in the previous message.
The "system-message-container" is related to Joomla and we do not generate such kind of content.
Now, you can see to modify the translation of "CART_EMPTY" into an empty text ; it should avoid that exact message to be displayed.. But it could affect some other aspects of HikaShop when it have to tell the user that is cart is empty.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.