I’m having this same issue: Add a calendar. Says it successfully added it. No added calendar shows. I have 2 previous calendars that were set up without a hitch, so it may be the fault of one of the plugin updates–the previous 2 were created quite some time ago, and the shortcode continues to work properly.
WordPress 3.05
Host: Lunarpages
Stout 1.1.1
Site: https://www.northprospectchurch.org
The site is in a subdirectory called Blog2