Slider images stopped showing up on theme(s)

For the linked site, one day in the last week the slider images and text started failing to show up. I have updated all plugins and upgraded Wordpress, but nothing seems to help. The site is using the WooThemes theme "Peddlar" that has this built in slider feature.
Update: I noticed the same thing has happened on another theme from WooThemes called "Function" that is used for another linked site, Both seem to use the same built in slider feature and have the same issue.