error log get_available_variations() on bool

Here’s an error in 1.7.4

[31-Jan-2023 04:25:22 UTC] PHP Fatal error: Uncaught Error: Call to a member function get_available_variations() on bool in /srv/www/***/public_html/wp-content/plugins/woo-bigpost-shipping/includes/admin/forms/templates/variable_product.php:2

Stack trace:

#0 /srv/www/***/public_html/wp-content/plugins/woo-bigpost-shipping/includes/admin/class-woobigpost-admin.php(476): require_once()

#1 /srv/www/***/public_html/wp-includes/class-wp-hook.php(308): Woo_BigPost_Admin->woobigpost_metabox_update()

#2 /srv/www/***/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()

#3 /srv/www/***/public_html/wp-includes/plugin.php(517): WP_Hook->do_action()

#4 /srv/www/***/public_html/wp-admin/admin-ajax.php(188): do_action()

#5 {main}

thrown in /srv/www/***/public_html/wp-content/plugins/woo-bigpost-shipping/includes/admin/forms/templates/variable_product.php on line 2