Media manager Error To view images

We are bulding a new website to our clients, and the blog will be the firt that user EB5, so the problem now is:

When you open a folder (any folder) in the media manager in order to view the images inside, this images doesn´t display, instead a blank space appears, if you select this "blank Space" you can use the image as usually, but of course this provide a UX problem.

Here the debug:

GET http://domain.com/es/ 503 (Service Temporarily Unavailable)jQuery.extend.style @ foundry.js:6755(anonymous function) @ foundry.js:6936jQuery.access @ foundry.js:4142jQuery.fn.extend.css @ foundry.js:6919(anonymous function) @ composer-5.0.30.optimized.js:28049jQuery.extend.each @ foundry.js:385jQuery.fn.jQuery.each @ foundry.js:138revealThumbnails @ composer-5.0.30.optimized.js:28038(anonymous function) @ composer-5.0.30.optimized.js:27103fire @ foundry.js:3119self.fireWith @ foundry.js:3231deferred.(anonymous function) @ foundry.js:3321fire @ foundry.js:3119self.add @ foundry.js:3165(anonymous function) @ foundry.js:3279fire @ foundry.js:3119self.fireWith @ foundry.js:3231self.parsers.resolve @ foundry.js:31084parse @ foundry.js:30981(anonymous function) @ foundry.js:30995jQuery.extend.each @ foundry.js:385(anonymous function) @ foundry.js:30994fire @ foundry.js:3119self.fireWith @ foundry.js:3231done @ foundry.js:9348callback @ foundry.js:9758

regafisioterapia.com/:1 GET http://domain.com/es/ 503 (Service Temporarily Unavailable)

We edited the "domain".

Data provided in a .txt file via dropbox.

Thanks as always.