Edit: Fix for 1.7.3.3: Comment-3185932
Edit: Fix for 1.7.6.5: Comment-3236846
Edit: Fix for 1.7.8.7: Comment-3404464
The online store that I maintain recently created a Prestashop 1.7 store and have been slowly migrating our products over. One thing that I have discovered is that Prestashop no longer seems to allow free orders. Our online store has a number of free virtual products and in PS 1.6 this wasn't an issue at all. You could add them to your cart and checkout as normal though it would recognize the order as free and bypass the payment step. Now however, in PS 1.7 if I only have a free item in the cart and proceed with checkout it gets to the payment step and won't allow you to proceed. There are no payment methods listed to select which is good however the "Order with an Obligation to Pay" button remains grayed out not allowing you to continue. Underneath the button it has the statement, Please make sure you've chosen a payment method and accepted the terms and conditions.
Can anyone else confirm that this is a bug? If so I'll file a bug report.
You can try this yourself on our store here, 3abnstore.com