Uncaught Error: Could not find module `ember-cli-htmlbars` imported from


I have been hunting down the error

loader.js:247 Uncaught Error: Could not find module ember-cli-htmlbars imported from somecomponent

in an addon for the last days after migrating to new ember version including octane.

Finally I found the cause:

  included: function (app, parentAddon) {

in the file index.js is causing the problem.

Any example how this should be changed now?

The example from Developing Addons and Blueprints leads to the error message above.

Example from In Repo Addons - Writing addons - Ember CLI Guides seams to work.