Instagram does not require an SSL certificate. If you have one, JFBConnect will use it, but it's not required. You should Check the "Disable implicit OAuth:" and Un-Check "Enforce signed header".
As for what's wrong, I just tried and I'm getting the error, "Redirect URI does not match registered redirect URI". Please double check your setting for "OAuth redirect_uri:" in your Instagram app. It should likely be:
http://www.opensourceliving.org/index.php
One thing I notice is that your site is accessible over www and non-www. I'd recommend redirecting one to the other as Instagram doesn't let you set two different domains, so one would work and the other likely would not.
I hope that helps, but if not, let me know what you've set for your Redirect URI setting.
Thanks,
Alex