I’ve just wasted some time.
I was using ember-data v1.13.2
And I’ve got some cryptic message:
Error while processing route: index serializer.get is not a function TypeError: serializer.get is not a function
Obviously, it means that Fixture Adapter has been removed 
You can read about it here - https://github.com/emberjs/data/blob/master/CHANGELOG.md#breaking-changes
Removed support for DS.FixtureAdapter. You can use it as an addon, or build it using Ember Giftwrap
I’m a little bit frustrated - why don’t gradually deprecate and/or provide better message for debugging? If you’ve done it - my apologies - but my feeling is that some of the examples / tutorials in the wild will break.
Take for instance - http://thetechcofounder.com/getting-started-with-ember-js-using-ember-cli/
My personal view is that for a start, for someone learning EmberJS, Fixture Data is very helpful as allows to replace server with a few lines of code / allows to focus on Ember rather than debugging gemfile or node_modules (you know the drill).
EDIT: Yes, as I’m using older version I see deprecation message:
DEPRECATION: DS.FixtureAdapter has been deprecated and moved into an unsupported addon: https…