Is something wrong with the WC_Order class?

Hi all.

I’ve just upgraded Woocommerce to v 3.03

I’m having trouble with a line of code:

$original_order = new WC_Order($original_order_id);

Which is giving

Fatal error: Uncaught Exception: Invalid order. in /home/developer1181/weirdsky.dreamhosters.com/goldenmean/wp-content/plugins/woocommerce/includes/data-stores/abstract-wc-order-data-store-cpt.php:86

The order_id I’m giving it is valid, and this piece of code used to work before the upgrade.

Any ideas as to what has happened?

Nick