matthiasV-21

Problem:
Fatal error when editing Languages

Solution:
Actually, the problem was coming due to "Site is Moved or Copied" message on top of the page. Since it is a staging site, I selected "This is a copy of my original site" and saved.

Relevant Documentation:
- https://wpml.org/documentation/translating-your-contents/advanced-translation-editor/using-advanced-translation-editor-when-you-move-or-use-a-copy-of-your-site/
- https://wpml.org/documentation/automatic-translation/using-automatic-translation-with-custom-languages/