Encountered a resource object with an undefined type

Ember Data
1

I’m trying to implement authentication after the user creation in an ember/rails-api I’m able to correctly add the user to the database, but I’m getting this in the console:

ember.debug.js:31321 Error: Assertion Failed: Encountered a resource object with an undefined type (resolved resource using ember-app@serializer:user:)

I do get back the correct json with my info:

{"data":{"token":"ezUR_NTxy7STEiiFhEx3","email":"test@email.com"}}

when I run in the console:

newUser.save()

Class {__ember1473012953664: "ember539", __ember_meta__: Meta}
  __ember1473012953664: "ember539"
  __ember_meta__: Meta
  __proto__: Class
  __ember1473012953664: "ember113"
  __ember_meta__: Meta
  _super: ROOT()
  catch: ()
  constructor: (subclass of Ember.ObjectProxy)
  content: (...)
  finally: ()
  isFulfilled: false
  isPending: ComputedProperty 
  isRejected: false
  isSettled: ComputedProperty
  promise: ComputedProperty
  reason: null
  then: ()
  __proto__: Class

isFulfilled is false… so the authenticate method is not even called:

newUser.save().then(function(response) {
        this.get('session').authenticate('authenticator:devise', newUser.get('email'), newUser.get('password')).catch((reason) => {
          this.set('errorMessage', reason.error);
        });
      });

Any chance someone could give me a hand?? Thanks in advance!!