Google chrome extension not showing the popup

Question

The problem is that when I click on the icon it doesn't show anything at all.

manifest.json

{
  "manifest_version": 2,
  "name"            :  "My cool plugin",  // the name of the extension
  "version"         :  "1.0"              ,   // version number
  "description"     :  "My cool plugin", // description used in the Chrome Webstore
  "background": "background.html",
  "browser_action"  :  {
    "default_title": "My cool plugin",
      "default_icon"   :  "icon.png",      // specifies the default icon
      "popup"          :  "popup.html"   // the page to show when the icon is clicked
  },
  "permissions": [
    "tabs", 
    "http://*/",
    "https://*/*"
  ]
}

popup.html and background.html

<div>
    Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
    quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
    consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
    cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
    proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
</div>

What is the problem?

Answer 1

it's "default_popup": "popup.html" not "popup"

https://developer.chrome.com/extensions/browserAction.html