Problem: The client is experiencing a fatal error when loading a variable product in the REST API, but not with a simple product. The error message indicates an issue with calling a member function on an array within the WooCommerce Multilingual plugin. Solution: We recommend deactivating all third-party plugins except for WooCommerce and WPML-related ones, and switching to a default theme like Twenty Twenty-Two to isolate the issue. This approach helped confirm that the problem might be caused by either a conflicting plugin or the theme currently active on your site. If this resolves the issue, you can reactivate each plugin one by one to identify the specific cause of the conflict.
Please note that this solution might be outdated or not applicable to your specific case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the problem persists, please open a new support ticket for further assistance at WPML support forum.
