Problem: The client wants their URL to include language codes in uppercase (e.g., domain.com/fr-FR/) during the initial setup of the WPML plugin. However, they encounter an error stating that only lowercase letters and '-' are allowed, which prevents them from setting uppercase language codes initially. Solution: We explained that all language codes should be in lowercase due to international standards and WordPress conventions. ISO 639 language codes must appear in lowercase, while country codes can be capitalized. The ability to add uppercase letters later in the 'edit language' section is identified as a bug and is scheduled for a fix. We recommend using lowercase language codes to avoid issues with translation files from other plugins and search engines.
If this solution does not resolve your issue or seems outdated, we recommend opening a new support ticket. We also advise 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 visit our support forum at WPML support forum.
