In “Registration link override” is not a tick. So micht Enabled!
Yes, as I said, not in the Pro version, registration worked, was displayed on the website. That's why I've bought the Pro version because it worked. Now with the Pro version, the registration page is no longer displayed (white side). I turn off the Pro version, the registration page will appear of course!
May be you can check the white page's source code if it gets any fatal error. There is one possibility of conflict with “reCaptcha”. May be it's loading the reCaptcha library again and possibly a fatal error. Thats what I can think about.