I've been playing around with Shortcodes UI, trying to understand how to build something there with PHP which I am brand new to, so I thought the fact that absolutely nothing was happening on the test posts where I was inserting a few widgets using some sample coding was me.
I decided to try the demo for the PayPal donation button, and it won't display either. The shortcode for the PayPal demo is currently at the link below, and to point out WHERE it should be, I added two sets of lines like this ----------, one above and one below the shortcode:
Using Safari's web inspector, I see this in the code, in the small blank space where the PayPal thing should be showing up:
<a href="https://firstname.lastname@example.org&item_name=Donation for The most awesome WordPress Plugin Ever!!!" title="The most awesome WordPress Plugin Ever!!!"></a>
Simple shortcodes WILL / DO display, however, such as one of the demos and a box I created, all of which you can see at the bottom of the same post.
Any ideas about what's going on?