com.facebook.react.bridge.ReadableNativeMap cannot be cast to java.lang.string

[Jukez17]

I keep getting this error when filling the form and pressing the register button.

`@firebase/firestore: Firestore (7.19.0): Could not reach Cloud Firestore backend. Backend didn't respond within 10 seconds.
This typically indicates that your device does not have a healthy Internet connection at the moment. The client will operate in offline mode until it is able to successfully connect to the backend.
[Tue Aug 25 2020 12:57:48.133]  ERROR    The action 'NAVIGATE' with payload {"name":"Home","params":{"user":{"id":"4Foqi2I28cTIosFxwnYNmPHD2g53","email":"[email protected]","fullName":"Jukka"}}} was not handled by any navigator.
`
`
import 'react-native-gesture-handler';
import React, { useEffect, useState } from 'react'
import { NavigationContainer } from '@react-navigation/native'
import { createStackNavigator } from '@react-navigation/stack'
import { LoginScreen, HomeScreen, RegistrationScreen } from '../screens'
import {decode, encode} from 'base-64'
if (!global.btoa) {  global.btoa = encode }
if (!global.atob) { global.atob = decode }

const Stack = createStackNavigator();

export default function App() {

  const [loading, setLoading] = useState(true)
  const [user, setUser] = useState(null)

  return (
    <NavigationContainer>
      <Stack.Navigator>
        { user ? (
          <Stack.Screen name="Home">
            {props => <HomeScreen {...props} extraData={user} />}
          </Stack.Screen>
        ) : (
          <>
            <Stack.Screen name="Login" component={LoginScreen} />
            <Stack.Screen name="Registration" component={RegistrationScreen} />
          </>
        )}
      </Stack.Navigator>
    </NavigationContainer>
  );
}`

`import React, {useState} from 'react';
import {Image, Text, TextInput, TouchableOpacity, View, ToastAndroid , Alert} from 'react-native';
import {KeyboardAwareScrollView} from 'react-native-keyboard-aware-scroll-view';
import styles from './RegisterStyle';
import { firebase } from '../../firebase/config'

export default function RegistrationScreen({navigation}) {
  const [fullName, setFullName] = useState('');
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [confirmPassword, setConfirmPassword] = useState('');

  const onFooterLinkPress = () => {
    navigation.navigate('Login');
  };

  const onRegisterPress = () => {
    if (password !== confirmPassword) {
      ToastAndroid.show("Passwords does not match!", ToastAndroid.SHORT);
      return
    }

    firebase
      .auth()
      .createUserWithEmailAndPassword(email, password)
      .then((response) => {
        const uid = response.user.uid
        const data = {
          id: uid,
          email,
          fullName
        }
        const usersRef = firebase.firestore().collection('users')
        usersRef
          .doc(uid)
          .set(data)
          .then(() => {
            navigation.navigate('Home', {user: data})
          })
      })

  };

  return (
    <View style={styles.container}>
      <KeyboardAwareScrollView
        style={{flex: 1, width: '100%'}}
        keyboardShouldPersistTaps="always">
        <Image
          style={styles.logo}
          source={require('../../../assets/icon.png')}
        />
        <TextInput
          style={styles.input}
          placeholder="Full Name"
          placeholderTextColor="#aaaaaa"
          onChangeText={(text) => setFullName(text)}
          value={fullName}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TextInput
          style={styles.input}
          placeholder="E-mail"
          placeholderTextColor="#aaaaaa"
          onChangeText={(text) => setEmail(text)}
          value={email}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TextInput
          style={styles.input}
          placeholderTextColor="#aaaaaa"
          secureTextEntry
          placeholder="Password"
          onChangeText={(text) => setPassword(text)}
          value={password}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TextInput
          style={styles.input}
          placeholderTextColor="#aaaaaa"
          secureTextEntry
          placeholder="Confirm Password"
          onChangeText={(text) => setConfirmPassword(text)}
          value={confirmPassword}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TouchableOpacity
          style={styles.button}
          onPress={() => onRegisterPress()}>
          <Text style={styles.buttonTitle}>Create account</Text>
        </TouchableOpacity>
        <View style={styles.footerView}>
          <Text style={styles.footerText}>
            Already got an account?{' '}
            <Text onPress={onFooterLinkPress} style={styles.footerLink}>
              Log in
            </Text>
          </Text>
        </View>
      </KeyboardAwareScrollView>
    </View>
  );
}
`
`import React, {useState} from 'react';
import {Image, Text, TextInput, TouchableOpacity, View, ToastAndroid} from 'react-native';
import {KeyboardAwareScrollView} from 'react-native-keyboard-aware-scroll-view';
import styles from './LoginStyle';
import { firebase } from '../../firebase/config'

export default function LoginScreen({navigation}) {
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');

  const onFooterLinkPress = () => {
    navigation.navigate('Registration');
  };

  const onLoginPress = () => {
    firebase
    .auth()
    .signInWithEmailAndPassword(email, password)
    .then((response) => {
        const uid = response.user.uid
        const usersRef = firebase.firestore().collection('users')
        usersRef
            .doc(uid)
            .get()
            .then(firestoreDocument => {
                if (!firestoreDocument.exists) {
                  ToastAndroid.show("User does not exist anymore.", ToastAndroid.SHORT);
                  return;
                }
                const user = firestoreDocument.data()
                navigation.navigate('Home', {user})
            })
    })
  };

  return (
    <View style={styles.container}>
      <KeyboardAwareScrollView
        style={{flex: 1, width: '100%'}}
        keyboardShouldPersistTaps="always">
        <Image
          style={styles.logo}
          source={require('../../../assets/icon.png')}
        />
        <TextInput
          style={styles.input}
          placeholder="E-mail"
          placeholderTextColor="#aaaaaa"
          onChangeText={(text) => setEmail(text)}
          value={email}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TextInput
          style={styles.input}
          placeholderTextColor="#aaaaaa"
          secureTextEntry
          placeholder="Password"
          onChangeText={(text) => setPassword(text)}
          value={password}
          underlineColorAndroid="transparent"
          autoCapitalize="none"
        />
        <TouchableOpacity style={styles.button} onPress={() => onLoginPress()}>
          <Text style={styles.buttonTitle}>Log in</Text>
        </TouchableOpacity>
        <View style={styles.footerView}>
          <Text style={styles.footerText}>
            Don't have an account?{' '}
            <Text onPress={onFooterLinkPress} style={styles.footerLink}>
              Sign up
            </Text>
          </Text>
        </View>
      </KeyboardAwareScrollView>
    </View>
  );
}
`

`(parameter) response: firebase.auth.UserCredential
Object is possibly 'null'`