Getting "The 128x128 icon file is missing" error when uploading app

[Radio Player UK]

Hello,

I'm trying to upload my Chrome app, but I keep getting "The 128x128 icon file is missing" error. I have the 128 x 128 image there, in .png format, in the same folder as my manifest.json file. Am I doing something wrong?

This is my code for manifest.json:

{

    "name": "Radio Player UK",

    "version": "1.0",

    "manifest_version": 2,

    "description": "Radio, but without the rubbish. The best radio stations are here. Choose from lots of great radio stations.",

    "app":{

        "urls": ["http://www.radioplayeruk.com"],

        "launch":{

            "web_url": "http://www.radioplayeruk.com/index.php"

        }

    },

    "icons":{

        "icons": { "16": "logo16.png", "128": "logo.png"

    }

}

}

I have attached a screenshot of the folder I'm trying to upload (obviously it will be zipped up before uploading).

Thanks for any help!

Mike