Image URL return a 404 error

Hello, i upload an image file using FTP and I've got a 404 error when i try to display it in the browser.

when I try with the FTP address it works
ftp://emoji@ftp.emoji.altervista.org/images/blank.jpg

but with HTTP it doesn't work.
http://emoji.altervista.org/images/blank.jpg

Permission File is 644

any idea?

I don't understand why, but now it works without doing anything.

You are using CloudFlare, remember to always activate the development mode when working on your website. Otherwise you'll look at some cached content.