Now, the problem:
I can redeem a coupon at Step 1 of my shopping cart. This works well.
The problem occurs when I reach the payment stage.
1. When I click "make a payment", the system craps out, I get a blank page and everything is erased from my cart when I go back.
2. As well, if the certificate is worth more than the value of my order, I am still prompted to choose a carrier at Step 4 of the payment process and when I try to go to the next screen I get the "Oops, something went wrong".
I turned on the default theme to test this and the problem persists regardless of theme.
I am using Prestashop 1.5.4 and I just bought the module this week.
I assume that I am not the first person to have this problem? What is the fix?
Thanks for any help.