Hey,
Thanks for replying. But I think this is not what I need.
I need the message in the shopping cart summary to tell the customer that the an item inside his/her cart is unavailable in the quantity he/she wants to buy.
He/she needs to adjust the quantity before proceeding to the next step of the check out process.
I remember the older prestashop versions had this. But I can't find it in 1.6.1.1