With all of the JFBConnect plugins disabled, which means that JFBConnect is inactive, the registration page still shows up like in your screenshot. This means another plugin or extension is causing the issue. If you have also recently upgraded any other extensions, please review your configurations for them to try to narrow down the issue.
For the time being, I have re-enabled our plugins, but to verify that this is not JFBConnect causing the problem, these are the plugins that I had disabled:
* Authentication - JFBConnect Social Integration
* Content - JFBCContent
* Installer - JFBConnect
* System - JFBCSystem
* User - JFBConnect Social Integration
-Melissa