I am using Membership 2 Pro and since today I am encountering the error displayed in the photo you see attached to this post. As I am not very good with finding the solution I did my best by trying to find the plugin which might be causing that error. I did also check the class-wp-user.php file which is supposed to be the cause here, but could'nt find anything.
The error occurs when you register on my subdomain http://move.susanne-gottschall.de/register. For testing purposes you can then use the code "LA76GRA" during checkout to gain free access and the error will occur after you then hit register!
I hope you can help me out with this one, I already tried deactivating all plugins that might interfere as I am using you very own "Html Email Template" and "Ultimate Branding" but unfortunately this didn't do the trick. Support Access is granted btw.
Thanks for you help! Can't wait to get this fixed!