WooCommerce Multilingual – Fatal Error When Saving a Translation in the Native WP Editor

Overview of the issue

When using WooCommerce Multilingual with WPML, you might experience the following fatal error when saving product translations using the native WordPress editor:

PHP Fatal error: Uncaught TypeError: Cannot access offset of type WP_Post in isset or empty in .../wp-content/plugins/sitepress-multilingual-cms/classes/core-abstract-classes/class-wpml-element-translation.php:282

Workaround

Please, make sure of having a full site backup of your site before proceeding.

• Open the …/wp-content/plugins/woocommerce-multilingual/classes/Synchronization/Hooks.php file.
• Look for line 184.
• Replace:

  $originalLanguage = $this->manager->getElementLanguage( $originalProduct );
          

• With:

  $originalLanguage = $this->manager->getElementLanguage( $originalProduct->ID );