This thread is resolved. Here is a description of the problem and solution.
Problem: The user was having duplicated fields in the Translation Editor. Solution: This was due to an inconsistency in the database. The issue came from an empty field in a serialized array saved on the "icl_sitepress_settings" option key in wp_options table. As you can see in the attached image to my private reply. The empty key should not be so, we need to patch it by replacing the empty key, with the value "test".
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