My version is the last es_ES.phar from the web unpacked with some slight corrections. I had the same problem in the past and I do not know any other way to solve it. As ntozier says, it seems a problem with the way your server manages phar files. If my solution works, fine for you.
There is no need to have a es_ES.phar file if you have the folder es_ES, you need just one of both.