A warning message on my products page

http://networking.cafe/store-2/products/

Products

Warning: getimagesize(): php_network_getaddresses: getaddrinfo failed: Name or service not known in /home2/ab29713/public_html/networking.cafe/wp-content/plugins/coursepress/includes/classes/class.shortcodes.php on line 1098

Warning: getimagesize(http://networking.cafe/wp-content/uploads/2015/08/ee0d896a14d2ab093ed6b11e79c11da5.jpg): failed to open stream: php_network_getaddresses: getaddrinfo failed: Name or service not known in /home2/ab29713/public_html/networking.cafe/wp-content/plugins/coursepress/includes/classes/class.shortcodes.php on line 1098