로그인 후 Error가 alert 되는 것은 계정의 문제인가요?

import React, { useState } from 'react'
import { useDispatch } from 'react-redux';
import { loginUser } from '../../../_actions/user_action';
import { useNavigate } from 'react-router-dom';

function LoginPage(props) {
    
    let navigate = useNavigate();


    //dispatch
    const dispatch = useDispatch();

    //state, 처음state = ""
    const [Email, setEmail] = useState("")
    const [Password, setPassword] = useState("")

    //event 발생할 때 state를 변경
    const onEmailHandler = (event) => {
        setEmail(event.currentTarget.value)
    }

    const onPasswordHandler = (event) => {
        setPassword(event.currentTarget.value)
    }

    //login 버튼 
    const onSubmitHandler = (event) => {
        //페이지 refresh 방지
        event.preventDefault();

        // console.log('Email', Email)
        // console.log('Password', Password)

        //보내줄 data
        let body = {
            email: Email,
            password: Password
        }

        //'loginUser'라는 action
        dispatch(loginUser(body))
            .then(response => {
                if(response.payload.loginSuccess) {
                    navigate('/'); //v.6
                    // props.history.push('/') //v.5
                } else {
                    alert('Error');
                }
            })