As the title says, I've just had about 13 sub-sites have new user registration disabled after Wordpress updated automatically. When you go to register you receive the message, "Registration is disabled."
I went to Network Settings > Settings > Registration Settings, and it shows that registration is disabled, but it also doesn't let me turn it back on (can't click the options to turn it back on.)
This message is there, "If registration is disabled, please set NOBLOGREDIRECT in wp-config.php to a URL you will redirect visitors to if they visit a non-existent site."
I opened wp-config.php from the parent site and searched for "NOBLOGREDIRECT" but it's not found in there...