Too many redirects occuring - From the events+ and marketplace plugins

I have a site...
That I have installed Events + & Marketplace (to use Stripe as a gateway)
However, everything seems fine, at first glance, but I get this ending screen...

This is what I'm getting on the front end before I click on Pay/checkout

Please let me know what I'm doing wrong. I will open / give support access in advance.
My client needs this registration up and running ASAP.
Thank you in advance,