ZenCart Checkout Process Stopped Working

When attempting to complete the checkout process the "continue checkout" button on the "Step 1 of 3 - Delivery Information" page doesn't take you to the next step, it only causes the page to refresh.

To test it: https://exploradorestv.com/shop/

Feel free to register to recreate the error.

I'm not sure what the problem is as it was working before. I can't recall any changes I made that would cause this problem to occur (the most that was done was the modification of CSS style sheets).

All help is appreciated.

Product has 0 weight ...

Checkout shows no Shipping Modules ...

Does 0 weight mean Free Shipping? If so, install Free Shipping freeshipper Shipping Module ...

If 0 weight does not mean Free Shipping, change the setting in Shipping/Packaging:

Order Free Shipping 0 Weight Status
If there is no weight to the order, does the order have Free Shipping?
0= no
1= yes

Note: When using Free Shipping, Enable the Free Shipping Module this will only show when shipping is free.

NOTE: Check if you have Zones set on your Shipping Modules that you have covered all Zones so that people can checkout ...

thank you!