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I keep getting the blank popup screen (desktop and mobile) any time I try to use the facebook connect feature.
I have been approved by facebook developers for my app. I have used JomSocial MANY TIMES but have not had this error in over 2 years. I've verified the info in facebook dev app section & confirmed it w/our site.
That was it! the IP stored in fb app whitelist was the issue. Once I removed the IP addresses from fb app settings...IT WORKED & has worked ever since.
I truly appreciate you, your obviously strong IT Rock Star status at JomSocial & Joomla admin troubleshooting skills, and quick response, too!