I have tried auth with angularfire2 but get a different error - ‘specified authentication provider is not enabled for this Firebase.’ My app can read from the Firebase database & I have enabled Password auth in the console and have incorporated in my app bootstrap. So I am not sure what I going on. Have not had time to pursue it today.
I do remember in one of the Firebase presentations at Googe I/O yesterday the presenter said FirebaseUI was in place for iOS and Android, and the coming for web. I am very excited about this capability.
I recommend submitting your question on Firebase Slack channel - they are very responsive there. Good luck.
I had some issues with another Firebase project relating to Auth when the migration from v2 to v3 happend. I started a new Firebase project and exported my JSON tree to it and it was fine again.
FirebaseUI fully supports all recent browsers. Signing in with federated providers (Google, Facebook, Twitter, Github) is also supported in Cordova/Ionic environments.