Widget Display Is Empty, No Posts

I'm currently testing this plugin on a local VM. Post Indexer has been installed and running for a while, so no issues there. After installing and activating this plugin, I added the widget with a title and viewed the page. The title displays, but no posts. I made sure to add new posts after activating this plugin to eliminate that as a possible reason.

I'm using this plugin on a closed, private WordPress installation for an Intranet, so I'm unfortunately not able to make the site accessible to outside eyes. And, at present, I'm testing the plugin on a local VM installation before I move on to testing on our development and testing servers.

Any thoughts as to what could be the possible culprit?