[Plugin: Content by Country] Just didn't work – shortcode didn't render

I installed the plugin and pasted the example shortcode into a page and a post, but didn’t get anything.

Is there another installation step?

I’m also getting a “You do not have sufficient permissions to access this page.” sometimes while trying to activate the plugin. I’ve disable all my other plugins to see if it might be a compatibility issue.

I may be missing something obvious…