Facebook API Error: This IP can't make requests for that application

For the IP error, you'll need to go to the Facebook App Area and edit your app. In the Settings -> Advanced area, make sure there are no IPs in the Whitelist fields and that should be fixed.

For the JFBCSystem error, please try disabling the Joomla caching and any other caching/optimization extensions (or settings in your template) that you may have enabled. That won't be necessary long-term, but it will help us narrow down what's preventing our system plugin from doing everything it needs to do. Let us know if that lets Autotune pass and we can go from there.

Thanks,
Alex