Around this time last year I solved a problem of my blog posts not having thumbnails when published to my Facebook page by manually setting featured images in the posts, as well as using the Facebook debugger to preview links.
Recently I have observed a rash of Facebook posts generated by other WordPress sites where the thumbnail is blank, as you can observe below in an older post of mine.
Thanks to Chuck Reynolds, there is a handy WordPress plugin that fixes that.
Add Chuck’s WP Facebook Open Graph protocol plugin to your WordPress instance and, after a brief configuration, you should never have your shared posts appear without a thumbnail.
Enjoy Renegade Soundwave‘s classic, “Biting My Nails,” while you improve your WordPress site: