Console error while testing

[holgergp]

TypeError: Cannot read property 'set' of null
at m (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:11:11830)
at l.create.set (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:13:21308)
at Concertember.ConcertController.Ember.ObjectController.extend.actions.addConcert (http://localhost:63342/concertEmber/app/scripts/controllers/concertController.js:46:18)
at n.create.send (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:13:6483)
at http://localhost:63342/concertEmber/test/spec/test.js:67:30
at a (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:12:1824)
at i (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:12:1743)
at c (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:12:2476)
at http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:13:11367
at e.invoke (http://localhost:63342/concertEmber/app/bower_components/ember/ember.min.js:11:24893)