Ember.js 1.13 no longer works in Internet Explorer 8

This is a bit of a P.S.A, as I’ve raised it with the Ember.js team, but they said they won’t be making any changes to the 1.13 branch.

Ember v1.x should support IE 8 out of the box, but due to a recent change in UglifyJS 2.7, and fact that Ember.js uses broccoli-uglify-sourcemap, which in turn specifies UglifyJS ^2.6, any new projects created with Ember.js 1.13 will not work in IE8. Full details can be found here - https://www.bugmuncher.com/blog/ember-js-in-ie8

In order to fix this, you need to edit the file ember-cli-build.js in the root of your project, and change:

var app = new EmberApp(defaults, {
  // Add options here
});

to:

var app = new EmberApp(defaults, {
  // Force UglifyJS 2.7.0 + to support IE 8
  minifyJS: {
    options: {
      compress: { screw_ie8: false },
      mangle:   { screw_ie8: false },
      output:   { screw_ie8: false }
    }
  }
});

As this will force UglifyJS to create IE8 compliant code.

Thanks matt, this is very helpful.