For me it works perfectly. Follow the steps and be sure to update the app-script to 0.48.
npm install firebase angularfire2 --save = > NO
npm install angularfire2 --save => YES.
Do not install firebase. Only install AngularFire2, not documented but Firebase is inside AngularFire2. Also when using firebase, you no longer need:
import firebase from firebase ->Do not do it.
My project goes this way without making any mistakes on the console. I hope I have helped.