Open Graph - Content Pugin doesn`t work

That line is trying to get information about the category that the article is in. Can you let me know if you're using the "Uncategorized" category for your articles, or real categories? I'm not sure why that error would be thrown, but the use of Uncategorized is my best guess as a starting point.

Let me know if there's anything about the category the article is in that may be unique to your site (or any plugins that operate on categories, etc). Any information you may have would help. This isn't an error we've heard of before, but we'll get you going.

Thanks,
Alex