Something's definitely wrong there, no doubt. The latest release of JFBConnect and SCLogin came out on Friday. It's possible we missed a conflict or other issue, and it looks like you may have found it.
To diagnose and resolve the issue, can you go to the Joomla -> Global Configuration area and set "Error Reporting" to 'Maximum'. Then, on the SCLogin configuration page, there should be a real PHP Error Message. That message will help us narrow down what's wrong and determine the proper solution to get you going.
Sorry for the trouble, but we'll get to the bottom of the problem quickly.
Thanks,
Alex