Login/Register

Hello,
I’ve freshly installed paidmembershipspro following the instruction video.

But the registration loop is not working for me.
When in a subscriber only area I click the Register button, I get redirected to the startpage of my site instead of a registration page.
I tried deactivating buddypress to see if it interferes with the plugin, and sure enough, it is another issue then, namely that I find myself at a 404 error page.
What could be the problem? does my themes functions.php need to be reconfigured ?

https://wordpress.org/plugins/paid-memberships-pro/