Warning .. is unreachable with URL rewriting on

I'm assuming that the "Search Engine Friendly URLs" is enabled in all cases? It doesn't really matter either way, but if it's disabled, the use rewriting setting doesn't do much anyways.

Either way, if rewriting is causing you problems, it's likely that you haven't renamed the htaccess.txt to .htaccess on your server (if you're using Apache). If you did rename that and are still getting that error, then the only other thing to try is to insert index.php into the url and see if that works. By that, I mean, if your SEF URL that isn't working looks like:
yoursite.com/good-looking/sef-url
to
yoursite.com/index.php/good-looking/sef-url
If that last URL works, then it means the .htaccess file hasn't been renamed or the .htaccess file is being ignored by your server for some reason.

Definitely not JFBConnect related, but we'll help how we can.

Thanks, and good luck,
Alex

Glad we could help diagnose things for you. We deal with a lot of issues all the time and have no problem helping our users with anything we can. Should you need anything else, just let us 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