PayPal Issue 'must specify valid values'

I have the software set to live mode and am using a free discount code, but it redirects to PayPal and gives the following error:

You must specify valid values for the A3, P3, and T3 parameters for a subscription.

I have no idea what this means. My plan is setup as a 30 day recurring, and I don't see anything for A3/P3/T3 in the PayPal area or in the plan area.

What am I doing wrong here?

Hi

At the moment, Membership Pro doesn't allow use 100% coupon discount for recurring subscription. The reason is because for recurring subscription, it needs Paypal handles payment and notify the system so that it can update status of the subscription records each time payment happens....

I will think about this case and improve it sometime next week. I think we can change the extension so that when you use 100% coupon discount for a recurring subscription, we can simply mark the record lifetime subscription.

Regards,

Tuan