I successfully created my own shortcode to display in Simple Pages. It works when the shortcode just displays simple text, and lets me put PHP/HTML in the shortcode, but when I go to view the page/page source, all of the PHP tags are commented out. This also happens for some basic Omeka shortcodes. I have HTML filtering turned off in the Security settings.
Possibly related issue: on my Plugins page, there’s no “Configure” button for Simple Pages.
Omeka version: 2.6.1
Simple Pages version: 3.1.1