Hi Melissa. Thanks for the prompt follow up.
1. Are you using the latest JFBConnect version 6.2.4?
Yes. Only installed it last week.
2. Can you tell me the exact URL of the page you're seeing this on?
lemiere.com/dream-diary/3-dream-diary-january-2015
Note down the bottom, next to comment section is the output: dream-diary/2015/01{/gallery}}
3. If you temporarily disable all of the JFBC plugins (auth, content, user, and system), is the gallery able to load correctly?
Yes. The Sigplus gallery loads fine (with or without JFBC)
4. Since it sounds like you're using our Content plugin, what are your settings in the JFBConnect > Social area for the article you're seeing this problem on - for instance position of comment/like, etc?
Yes. Played with the plugin content tags, as wanted to see how Virtuemart might handle JFBConnect within a product. Not using the JFBConnect tags though in the URL provided however.
5. Do you have any of our other plugins enabled, such as the Open Graph plugins?
Ah-Ha!! Searched under Plugin Manager for open graph, and yes, what look like default plugins, I had enabled:
Open Graph - Custom Object & Open Graph - Content
Sorry, just figured they needed to be turned on. Have now turned them OFF, and all works fine. Guess they conflicted with JFBConnect ...
6. What content component are you using - Joomla articles or K2 items?
Just plain old Joomla article.
Thanks for your help. The diagnostic list of questions has solved the problem. Have now left the Open Graph plugins turned off, so you won't see the error any more. =)