If you create a coupon which blocks use on, for example, a sale item, it doesn't warn the customer that it won't be applied.

It states that the voucher is 'applied', the redeemed discount is '25%', but the value of the basket remains the same.

Can this be changed so that the coupon won't show as applied and have a warning message appear stating the coupon cannot be used against one or more items in the basket?

I am not sure why this wasn't instated in the first instance? It's confusing for customers and will result in more customer queries. Thanks