This morning, I and other users had access to this file: w:c:es.la-mano-del-diablo:Archivo:Diablo_editions.PNG (see [http://es.la-mano-del-diablo.wikia.com/index.php?title=Especial:Registro&page=Archivo%3ADiablo%20editions.PNG logs), but now the file is vanished, and there's nothing in the deletion log.
The file was a screenshot of suspicious "hidden revisions" actions on a particular wiki: http://es.smashbros.wikia.com/wiki/Especial:Registro?offset=20180702024358 (see the removed logs). One usually hides the username of a vandal, but in this case it wasn't vandalism. Those entries were removed several hours after they happened, and several users already saw what was posted there. Even if the username that posted the messages was offensive (which wasn't), the entire log is removed, even the user that performed the deletion (which is the same user that hid the entire log).
Does anybody know how it's possible that a file gets vanished after it has been viewed by users, without any logs about it's deletion?