One of the products selected has already been ordered. If so, it can't be modified for the order placed neither it could be in the future. There are already printing files made for this particular product that can't be changed. If you want to modify a product ordered, you will need to place a new design request to create a "B" version.

You already have a pending touchup request. We can only manage one request at a time.

One of the products is published. A bit like the "already ordered" mention, if a product is published and can be bought with the design you approved to Publish, it can't be modified. You will need to Unpublish the product(s) and then asked for the touchups. You will be able to Publish it again once the modifications are done.