Stumbleupon button not working

When you mouse over the Stumbleupon button it’s not clickable. All the other buttons are working fine. I tried deleting and re-installing the plugin with no luck.

Here it is not working on a post: http://neatstuff.info/vegan-gluten-free-peanut-butter-chocolate-chip-cookies

Thanks for any help!

https://ww.wp.xz.cn/plugins/simple-share-buttons-adder/