THERE IS A VERY SERIOUS ERROR WHEN TRYING TO USE THE COUPON FUNCTION

Hello Everyone,

I made a coupon for 50% off for one of my subscription.

I'm using the pop-up registration form. Now, when a user registers with username, email, and password and clicks register, it goes to the payment pop-up where they have the option to enter in the coupon.

The problem begins when they enter the coupon and clicks apply coupon, the current pop-up window closes and goes back to the first registration pop-up.

When I check the users in my Wordpress Control Panel, i see the new user is registered but as the default free member not the paid member. Also, when i check the coupon, settings i set it to a maximum 10 uses, but zero has been used.

I tried several different combinations, but i've been getting the same result.

I need to new user to apply coupon and then go to paypal so they can pay the difference.