The Extension Check and Autotune both communicate using XML files being passed back and forth. My best, initial guess, is that there's an issue communicating with SourceCoast.com to fetch the right information. Do you have a firewall or anything else that would block outgoing connections? That would make sense if improper (or no) XML was being returned.
If you were using a previous version of JFBConnect, then Autotune or the Extension Check aren't required. Your app should already be configured and hopefully the extensions are up-to-date since you just upgraded. There's no requirement to use Autotune and connect to our server for updated information, it just helps get things going quicker.
Some things to test to diagnose the problem on the front-end. I'm assuming you're getting a white-page, but if it's something else (an error message, functionality not working, etc), let us know:
1) If you're using Profile Plugins, make sure you updated those to 4.2.x as well
2) Set "Error Reporting" in the Joomla Global Configuration area to "maximum". Check your front page. If an error is reported, let us know what that is and we can help you narrow down why you're getting it.
3) Check if you have any firewalls or other 'security' extensions or server configuration stuff enabled that would prevent communication with either sourcecoast.com or facebook.com
4) Go to Help->System Information and then "PHP Information". Search for "SimpleXML" and make sure it says that it's enabled.
Hope that helps get you started,
Alex
Error in autotune-setup and overview
