Benjamin,
Can you let me know:
* A site where you have JFBConnect configured for Instagram authentication
* What version of JFBConnect you are using?
That message means that your Instagram application information isn't setup properly with your domain. Once we know more about your site and JFBConnect version, we should be able to help narrow down what you should be entering in the Instagram settings area so you can verify your configuration.
Finally, please post from the account you subscribed to JFBConnect from. Priority support is for subscribers only, and when you post from your account, we can look up most of the information we ask above.
Thanks,
Alex