Problem: You are setting up WPML for the first time and have enabled translation for custom post types created with the ACPT plugin. However, when these are enabled, the Translation Management page crashes Solution: First, ensure that the custom post types are compatible with WPML. Although not officially tested by our team, the ACPT plugin, has developed an integration with WPML. You can find more details here: https://docs.acpt.io/integrations/wpml
But you need to make sure that the 'hierarchical' parameter for your custom post types is explicitly set to either true or false during registration. If this parameter is omitted, it may default to null, causing the error.
If these steps do not resolve your issues or the solution seems outdated, please check related known issues at https://wpml.org/known-issues/, verify the version of the permanent fix, and confirm that you have installed the latest versions of themes and plugins. If problems persist, we recommend opening a new support ticket at our support forum.
