ember-websockets | Ember.js websockets and socket.io addon | Addon library

The problem you had is most probably using ^ for your dependencies. What ^ (caret) does is upgrading your dependencies to a major version when you do a clean install. For instance if your dependency to an addon is let's say 1.2.0 and you used ^1.2.0 and there is a new version available 1.3.0, you will get this new major version. If you use ~ (tilda) instead of ^, then you will not get 1.3.0 but 1.2.2 for instance if available. In order to use the exact versions so that your dependencies will not change when you do a clean npm install, you can remove both caret and tilda in your dependency definitions.

In order to figure out which of your dependencies is outdated you can use npm outdated.

You are using latest ember-cli version 2.11.1, You can see all differences here https://github.com/ember-cli/ember-new-output/compare/v2.4.0...v2.11.1

As you can see, they removed the below dependencies from bower to package.json, so you have to remove this from your bower.json