Fatal error while editing pages

I have the same problem, but also found a temporary workaround. I commented out lines 141-144 in bambora-online-checkout.php which seemed to active the problem code. It can be changed in the plugin file editor at your own risk. It did solve my problem and I couldn’t see any immediate bad effects of this. Here is the change I did (adding /** and */):

140                        if ( is_admin() ) {
141   /**                          add_action( ‘add_meta_boxes’, array(
142                                        $this,
143                                        ‘bambora_online_checkout_meta_boxes’
144                                ) ); */
145                                add_action( ‘woocommerce_update_options_payment_gateways_’ . $this->id, array(
146                                        $this,
147                                        ‘process_admin_options’
148                                ) );

Here is the stack trace I received:
Uncaught Exception: Invalid order. in /home/silverfishno/silverfish.no/public/wp-content/plugins/woocommerce/includes/data-stores/abstract-wc-order-data-store-cpt.php:120

Stack trace:

#0 /home/silverfishno/silverfish.no/public/wp-content/plugins/woocommerce/includes/class-wc-data-store.php(159): Abstract_WC_Order_Data_Store_CPT->read()

#1 /home/silverfishno/silverfish.no/public/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-order.php(128): WC_Data_Store->read()

#2 /home/silverfishno/silverfish.no/public/wp-content/plugins/bambora-online-checkout/bambora-online-checkout.php(1403): WC_Abstract_Order->__construct()

#3 /home/silverfishno/silverfish.no/public/wp-includes/class-wp-hook.php(310): Bambora_Online_Checkout->bambora_online_checkout_meta_boxes()

#4 /home/silverfishno/silverfish.no/public/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()

#5 /home/silverfishno/silverfish.no/public/wp-includes/plugin.php(517): WP_Hook->do_action() #6 /home/silverfishno/silverfish.no/public/wp-admin