We are having the same issue today! I use the plugin on many sites that are fine, I have not touched them in awhile so I have not had to re-save anything. I installed the plugin today on one of my sites and i tried to save the settings with no luck at all.
I disabled all my plugins except for it and it still would not save the changes.
So the Pin shows on all my pages and post and images.
I tried to changed to color and size of the hover image pin with no luck.
Version 2.3.5 of the plugin
Wordpress version : 4.4.2
Genesis FRamework..