Hi I am using zen cart version 1.3.9d and I installed the latest mod 2.0c1. I am having issue after filling in the details on the billing. I tried to click continue checkout, it will refresh the Billing page. No matter how many times I tried keying in the information in the billing page, it still stuck at the Billing page after I press the continue checkout button.

Can someone kindly help me?

Thanks.