Very glad to hear we got you going. I'm completely unsure of why that language string would be causing that issue, but I'm glad to hear you got it going. As always, should you need anything else, just let me know.
Finally, if you haven't already, please consider leaving a rating and review for JFBConnect, or our support, on the Joomla Extension Directory. It certainly isn't required, but is very appreciated:
extensions.joomla.org/extensions/social-...ook-integration/7215
Thanks,
Alex