I donated to the plug-in as it's been doing wonderfully for me to climb up the search engine rankings. I had a problem with Facebook not showing my thumbnails/meta descriptions anymore.
I figured out how to get Facebook to show thumbnails again and have selected a page to use as Facebook admin. Whenever I use Facebook's debug page though:
it comes back with a 404: Bad Response Code: URL returned a bad HTTP response code.
It also has 3 warnings:
Inferred Property: The 'og:url' property should be explicitly provided, even if a value can be inferred from other tags.
Inferred Property: The 'og:title' property should be explicitly provided, even if a value can be inferred from other tags.
Tiny og:image: All the images referenced by og:image must be at least 200px in both dimensions. Please check all the images with tag og:image in the given url and ensure that it meets the minimum specification.
All of the warnings seem like the og: settings are set correctly when I view source.
Any idea how I can get rid of the error and warnings?