Translation string "Internal" is duplicate for authentication and event. For authentication one is appeared first, "Internal" for event type is not translatable.

#: include/users.inc.php:58
#: include/views/administration.authentication.edit.php:35
#: include/views/configuration.action.list.php:36
msgid "Internal"
msgstr "Internal"

#: include/events.inc.php:37
msgid "internal"
msgstr ""