Memberships / Paypal IPN issue

Hi, I'm using Multisite with plugins Buddypress/Events Manager/Memberships/Classifieds.

I am having a problem connecting subscribers in Memberships to paypal for payment. The IPN is correct, I'm in live mode. When I connect to paypal for payment via Events Manager it processes and routes back to the site properly. I deactivated this plugin and tested, and still Memberships does not connect to paypal, just reroutes to the homepage. We are also using Classifieds as a free listing service.

Any idea what this could be about?