Error

import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import com.google.firebase.auth.FirebaseAuth;
import com.rengwuxian.materialedittext.MaterialEditText;

public class LoginActivity extends AppCompatActivity {


    MaterialEditText et_email, et_password;
    Button loginBtn;
    Toolbar toolbar;
    String email, password;
    FirebaseAuth mAuth;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);


        toolbar = findViewById(R.id.toolbarlogin);
        setSupportActionBar(toolbar);
        getSupportActionBar().setTitle("Вход");
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        et_email = findViewById(R.id.log_email);
        et_password = findViewById(R.id.log_password);
        loginBtn = findViewById(R.id.login_account);


        mAuth = FirebaseAuth.getInstance();


        loginBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                email = et_email.getText().toString();
                password = et_password.getText().toString();


                if (TextUtils.isEmpty(email)) {

                    et_email.setError("Введите почту");

                } else if (TextUtils.isEmpty(password)) {

                    et_password.setError("Введите пароль");
                } else {
                    LoginMeIn(email, password);
                }
            }
        });
    }

    private void LoginMeIn(String email, String password) {


        mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(task -> {

            if (task.isSuccessful()) {

                Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(intent);
                finish();
                Toast.makeText(LoginActivity.this, "Успешны вход", Toast.LENGTH_SHORT).show();
            }
        });
    }
}