market press fatal error

I'm getting an error on the product pages
http://labodegaimports.com/store/products/category/decorative-glass

Error
Catchable fatal error: Object of class WP_Error could not be converted to string in /homepages/21/d369233008/htdocs/wp-includes/formatting.php on line 2583

Any help would be appreciated. I haven't changed anything or edited the site in some time.

Malinda