Big changes today, all to make the messaging system more efficient. Previously, ember-message-bus attempted to trigger its events on all subscribers, which could be a huge array. Now, it uses a map with keys for each event name. Unfortunately, this results in a big api change.
Specifically, the BusPublisherMixin and BusSubscriberMixin are no longer supported. Instead, of calling this.publish and this.on, you'll need to call this.get('messageBus').publish and this.get('messageBus').subscribe. If you were using Ember.on to wrap your callbacks directly, you'll now need to register them manually, probably in the init hook. Checkout the first section of the readme for an example.