Firefox OS: Error submitting app

I'm trying to validate my app in the firefox marketplace. However, I am getting the following news: Error extracting the manifest from the zip file. But the manifest.webapp complies with the firefox standard

  {
  "name": "Primeiro APP Firefox OS",
  "description": "meu primeiro app",
  "launch_path": "/run.html",
  "icons": {
    "60": "/img/icon-60-2.png",
    "128": "/img/icon-128.png"
  },
  "developer": {
    "name": "alex jose silva",
    "url": "http://www.alexjosesilva.com"
  },
  "default_locale": "Pt-br"
}

Any suggestions how can I fix this?