The function wp_get_theme() is a new wordpress function for WordPress version 3.4. The error means the theme you have is looking for the function and the version of wordpress you are using is older than 3.4.
You can update your wordpress via the wp-admin and then you should be all set.
|Email:||support@WebHostingHub.com||Ticket:||Submit a Support Ticket|
|Chat:||Click To Chat Now|