It might indicate an error sourcing from the code still.
The only thing I can think of in this case is that maybe the “wpml_get_language_information” function is not available at the time of execution, the other lines should not throw any error messages.
Make sure that you don't have the custom ajax handler option activated on the Compatibility Settings plugin submenu: https://i.imgur.com/g5WZ23V.png
If that's not it, then I will have to see it in order to be able to tell what might be causing the problem. In that case if you can provide temporary admin and FTP details to your test environment, it would help me a lot.Best,
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