Why do I receive “unrecognized selector sent to instance“ in React Native iOS?

My code works perfectly on Android but it shows an error in iOS.

Error in iOS:

I couldn’t understand this error; is it related to AsyncStorage?

Why this happening on iOS devices?

First File

My imports

import React, {Component} from 'react';

import { Alert, Dimensions, Image, TouchableOpacity, AsyncStorage } from 'react-native';

import { Container, Body, Footer, Header, Input, Item, Left, Text, Title, Right, View, Button, Label, Form} from 'native-base';

import { SimpleLineIcons, Ionicons } from '@expo/vector-icons';

import { NavigationActions } from 'react-navigation';

import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view';

import { LinearGradient } from 'expo';

import { StatusBar } from "react-native";

import { Grid, Row, Col } from 'react-native-easy-grid';

import Toast, {DURATION} from 'react-native-easy-toast';

import Strings from '../utils/Strings';

var width = Dimensions.get('window').width;

export default class Login extends Component {
    static navigationOptions = {
        header: null
    };

    constructor() {
        super();
        this.state = {
            MobileNo: '',
        };
    }

    login = () => {
        AsyncStorage.setItem('mobileno', MobileNo);

        const { MobileNo } = this.state;
        console.log("Expected login number " + MobileNo);

        fetch('http://demo.weybee.in/Backend/controller/User_Login.php', {
            method: 'POST',
            headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                mobileno: MobileNo
            })
        }).then((response) => response.json())
        .then((responseJson) => {
            // If server response message same as Data Matched
            if(responseJson != 'Enter valid phone number') {   
                const { navigation } = this.props;
                // Then open Profile activity and send user email to profile activity.
                this.props.navigation.navigate('ForgetPass');
            } else {
                this.refs.toast.show('Invalid Number', DURATION.LENGTH_LONG);
            }
        }).catch((error) => {
            console.error(error);
        });
    }
}

Second File

My imports

import React, {Component} from 'react';

import { Alert, Dimensions, Image, TouchableOpacity, AsyncStorage } from 'react-native';

import { Container, Body, Footer, Header, Input, Item, Left, Text, Title, Right, View, Button, Label, Form} from 'native-base';

import { SimpleLineIcons, Ionicons } from '@expo/vector-icons';

import { NavigationActions } from 'react-navigation';

import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view';

import { LinearGradient } from 'expo';

import { StatusBar } from "react-native";

import { Grid, Row, Col } from 'react-native-easy-grid';

import Toast, {DURATION} from 'react-native-easy-toast'

import Strings from '../utils/Strings';

import OtpInputs from 'react-native-otp-inputs';

var width = Dimensions.get('window').width; 

export default class Login extends Component {
    static navigationOptions = {
        header: null
    };

    constructor() {
        super();
        this.state = {
            MobileNo: '',
            mobileNumber: '',
            code: '',
        }
    }

    componentDidMount() {
        AsyncStorage.getItem('mobileno').then((mobileNo) => {
            if(mobileNo){
                this.setState({ mobileNumber: mobileNo });
            }
        });
    }

    PTP = () => {
        let mobileNumber = JSON.parse(this.state.mobileNumber);
        console.log("login number " + mobileNumber);

        let {code} = this.state;
        console.log(code);

        fetch('http://demo.weybee.in/Backend/controller/Get_PTP.php', {
            method: 'POST',
            headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                mobileno: mobileNumber,
                code: code,
            })
        }).then((response) => response.json())
        .then((responseJson) => {
            // If server response message same as Data Matched
            if(responseJson != 'Enter valid phone number') {     
                const { navigation } = this.props;
                // Then open Profile activity and send user email to profile activity.
                this.props.navigation.navigate('Home');
            } else {
                this.refs.toast.show('Invalid PTP', DURATION.LENGTH_LONG);
            }
        }).catch((error) => {
            console.error(error);
        });
    }
}