SCLogin modal popup button does not allow user to register

That's almost always caused when the jQuery and/or Bootstrap libraries are being loaded incorrectly on the page. That can be multiple versions, incompatible versions or other variations of conflicts.

To fix, please try enabling the "Include jQuery/Bootstrap" setting in JFBConnect. That will include a specialized version of those libraries that only JFBConnect can use. It will ensure no conflicts with other extensions and other extensions won't conflict with JFBConnect or SCLogin.

I hope that helps,
Alex