Installing this update immediately caused my site to crash when either creating an order or adding items to an order in the admin pages. Error below, removing the site name and order number which this happened on. It happened multiple times in a row, immediately resolving when I rolled back the update.
An error of type E_ERROR was caused in line 945 of the file MYSITE/wp-content/plugins/atum-multi-inventory/classes/Inc/Orders.php. Error message: Uncaught Error: Call to a member function get_id() on int in /MYSITE/wp-content/plugins/atum-multi-inventory/classes/Inc/Orders.php:945
Stack trace:
#0 /MYSITE/wp-includes/class-wp-hook.php(324): AtumMultiInventory\Inc\Orders->calculate_update_mi_order_lines(ORDER#, Array)
#1 /MYSITE/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#2 /MYSITE/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#3 /MYSITE/wp-content/plugins/woocommerce/includes/admin/wc-admin-functions.php(306): do_action('woocommerce_bef...', ORDER#, Array)
#4 /MYSITE/wp-content/plugins/woocommerce/includes/admin/meta-boxes/class-wc-meta-box-order-items.php(53): wc_save_order_items(ORDER#, Array)
#5 /MYSITE/wp-includes/class-wp-hook.php(326): WC_Meta_Box_Order_Items::save(ORDER#)
#6 /MYSITE/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#7 /MYSITE/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#8 /MYSITE/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-meta-boxes.php(262): do_action('woocommerce_pro...', ORDER#, Object(WP_Post))
#9 /MYSITE/wp-includes/class-wp-hook.php(326): WC_Admin_Meta_Boxes->save_meta_boxes(ORDER#, Object(WP_Post))
#10 /MYSITE/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#11 /MYSITE/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#12 /MYSITE/wp-includes/post.php(5110): do_action('save_post', ORDER#, Object(WP_Post), true)
#13 /MYSITE/wp-includes/post.php(5212): wp_insert_post(Array, false, true)
#14 /MYSITE/wp-admin/includes/post.php(453): wp_update_post(Array)
#15 /MYSITE/wp-admin/post.php(227): edit_post()
#16 {main}
thrown