Can you double-check that you've set up the twitter application correctly by following
our guide
? Specifically, I would first look at the API/Secret Keys, Callback URLs and 3-legged auth and make sure they're correct
Also, can you go into the JFBConnect backend > Configuration > Advanced section and set Debug Mode to On and try again? If there's an error in the request to Twitter, it should show on the page.
-Melissa