I wanted to study the way the "Allow new registrations" options work in the Admin Panel but everytime I chose either one of the options:
Only user account can be created.
Only logged in users can create new blogs.
I would receive a message saying:
"Are you sure you want to do this? Please try again."
On the Wordpress forum there are many messages about this but I could find no solutions. So, I tracked the problem to the nonce code in functions.php and pluggable.php. It seems that my nonce was expired. I forced the code to return as though it succeeded and was able to continue. When I restored the code expecting to see the "Are you sure..." message again the system was OK. Can someone tell me if the nonce gets regenerated occasionally? That might explain the sudden recovery. And what is the nonce used for? A security mechanism?