<Firebase addAuthStateListener not getting called ...

# stackoverflow

[user]

Firebase addAuthStateListener not getting called in kotlin
I'm trying to call addAuthStateListener but it's not working in kotlin. and also AuthUI not working properly. Every time I try to run this code I'm getting a runtime error. And the application force closed. I tried to get some help in firebase documentation but I'm not found anything that helps me.

import android.app.Activity
import android.content.Intent
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import com.firebase.ui.auth.AuthUI...