Problem: The client is experiencing a JavaScript error 'TypeError: Cannot read properties of undefined (reading 'indexOf')' while editing a custom field in their WordPress site using WPML and ACF. Solution: 1. We recommend confirming if the issue persists when only WPML plugins and ACF are active, with all other plugins and custom code disabled. 2. If the problem continues, provide a staging site for further investigation. Ensure to back up your site before making any changes. 3. Consider checking if the issue might be related to the browser, device, user, or location used for accessing the site. 4. Ensure that ACF field groups translation settings are set as not translatable to avoid issues. More details can be found here: Advanced Custom Fields field group should be set as not translatable.
If this solution does not resolve your issue or seems irrelevant due to being outdated or not applicable to your case, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent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. For further assistance, please open a new support ticket.
