Problem: The client is experiencing a 504 timeout error when using Custom Post Type UI (CPTUI) with Advanced Custom Fields (ACF) on a WPML staging site. The issue persists despite various tests and disabling other plugins. The error seems related to a conflict between a custom post type named 'Products' and WooCommerce Products. Solution: We recommended increasing the PHP Time Limit to 300 from 120 to see if it resolves the timeout issue. We confirmed that CPTUI is compatible with WPML and there are no known issues causing a 504 error between these plugins. We provided a sandbox environment for the client to test CPTUI and ACF without migrating the full site, which can help determine if the issue is related to the hosting environment or the plugins themselves. Access the sandbox here: Sandbox Login Link
If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix,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 at WPML support forum.
