Cristian Lavaque on "[Plugin: s2Member Framework (Member Roles, Capabilities, Membership, PayPal Members)] PayPal: "The unsubscribe button you clicked is invalid""

I'm glad there's some progress.

Are you generating those with s2Member's shortcodes for PayPal buttons, or from PayPal's site? WP Admin -> s2Member -> PayPal Buttons -> Subscr. Cancellation