Firefox Add-On Builder: ModuleNotFoundError

I'm trying to create a Firefox add-on using Mozilla's Add-On Builder, but when I try to use simple code from the documentation:

var sidebar = require("sdk/ui/sidebar").Sidebar({
  id: 'my-sidebar',
  title: 'My sidebar',
  url: require("sdk/self").data.url("sidebar.html")
});

I receive the following error:

enter image description here

"ModuleNotFoundError: unable to satisfy: requries(sdk/ui/sidebar) from ....."

Currently I'm using the default SDK 1.14 in the Add-On Builder

Solution

This is because Builder has not been updated since SDK 1.14 and is attempting to find the sidebar library which is only available in Firefox 26.

My best suggestion would be to download the current beta of SDK 1.15 and use the command-line:

Once you have downloaded the SDK, please see the installation documentation for how to get things going: