Invalid translation language

I can not publish anything for this error:

[30-Sep-2016 16:34:01 Europe/Rome] Uncaught PHP Exception DrupalCoreEntityEntityStorageException: “Invalid translation language (it) specified.” at /home/mysite/public_html/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php line 770

How do I fix it?

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/22/feed