[Resolved] CHANGING LANGUAGE CODE

Problem:
The client needed to change the language code for Chinese(Simplified) from "Zh-hans" to "zh", noting that there were no translated pages or posts in Chinese(Simplified).
Solution:
We informed the client that it is not possible to edit the language code of default languages. Instead, we recommended adding a new custom language for Chinese(Simplified) with the desired custom language code "zh". Since the client mentioned there was no content in Chinese(Simplified), they could duplicate the existing "Zh-hans" content to the new custom language "zh". We provided a link to our documentation for further guidance on how to assign or change language codes to existing content:
https://wpml.org/faq/how-can-i-assign-or-change-language-code-to-existing-content/

Please note that this solution might be irrelevant if it's outdated or not applicable to your case. If you find that this solution does not solve your issue, 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 you still need assistance, please do not hesitate to open a new support ticket with us.