catchbox-pro install problem

Hello, I followed the instructions "Installation using the WordPress Administration Panel" from 'http://catchthemes.com/theme-instructions/catch-box-pro/' All seems fine as the message "Theme installed successfully." appears. However, when activating the theme, the following message appears in the error log and leaving me with a non-functional WP: [Fri Mar 07 16:45:54 2014] [error] [client 192.168.1.183] PHP Fatal error: Call to undefined function wp_get_theme() in /usr/share/wordpress/wp-content/themes/catch-box-pro/update_notifier.php on line 13 I am running WP on a ubuntu 12.04 machine. All themes installed with the online install work fine. Can you please let me know how to correct this problem. thanks! joost