Upgrade to 4.3.8 Error

When upgrading from 4.3.7 to 4.3.8, the following error occurs when navigating in WP admin.

Uncaught Error: syntax error, unexpected ‘|’, expecting ‘;’ or ‘{‘
in /www/wp-content/plugins/markup-by-attribute-for-woocommerce/src/utility/general.php on line 361

Call stack:

1. mt2Tech\MarkupByAttribute\Autoloader::autoload('mt2Tech\MarkupByAttribute\Utility\General')
2. spl_autoload_call('mt2Tech\MarkupByAttribute\Utility\General')
   wp-content/plugins/markup-by-attribute-for-woocommerce/markup-by-attribute-for-woocommerce.php:162
3. mt2Tech\MarkupByAttribute\mt2mba_main('')
   wp-includes/class-wp-hook.php:324
4. WP_Hook::apply_filters('', array)
   wp-includes/class-wp-hook.php:348
5. WP_Hook::do_action(array)
   wp-includes/plugin.php:517
6. do_action('woocommerce_init')
   wp-content/plugins/woocommerce/includes/class-woocommerce.php:875
7. WooCommerce::init('')
   wp-includes/class-wp-hook.php:324
8. WP_Hook::apply_filters(NULL, array)
   wp-includes/class-wp-hook.php:348
9. WP_Hook::do_action(array)
   wp-includes/plugin.php:517
10. do_action('init')
    wp-settings.php:730
11. require_once('/wordpress/wp-settings.php')
    wp-config.php:107
12. require('/www/wp-config.php')
    wp-config.php:5
13. require_once('/wordpress/wp-config.php')
    wp-load.php:50
14. require_once('/wordpress/wp-load.php')
    wp-admin/admin.php:35
15. require_once('/wordpress/wp-admin/admin.php')
    wp-admin/tools.php:40