Placed wrong Jquery library

I had the same problem. The donate box is on top of the delete button so you can’t see it. Try right clicking the donate box and inspect element in your browser.
Add the following style to the page:
.spacker-donate { display: none; }
This should hide the yellow donate box temporarily so you can see the delete buttons. Remove whatever you need to before reloading the page, which will bring the donate box back in view.

I know this isn’t a great fix, but hopefully the developer can move the donate box to either the top or bottom of the page so it doesn’t interfere with the operation of the plugin.