Problem: The client is experiencing an issue where the 'Other texts (Strings)' section in WPML > Translation Management does not load strings and continuously displays 'Loading items...'. This is due to PHP Warnings being returned instead of valid JSON from the endpoint. The warnings are caused by undefined array keys in the PHP code handling the data. Solution: We discovered that switching the theme resolved the issue, indicating that the problem was related to the custom theme used. Additionally, deleting the strings in WPML > String Translation that were waiting for a translator resolved the issue. We recommend checking if any custom theme or plugin might be overriding PHP error settings and causing warnings to display. If the problem persists, consider deleting strings waiting for translation in WPML > String Translation.
Please note that this solution might be outdated or not applicable to your specific case.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 issue persists, please open a new support ticket at WPML support forum.