The component for route 'test' must be a React component

import MyScreen from './MyScreen';
...
test: MyScreen,
}

"react":16.8.4
"react-native":0.59.4
"react-redux": "7.0.2",
"redux": "4.0.1",
"react-navigation": "2.18.2",

import React, { Component } from 'react';
import { Text, View,Button} from 'react-native';
import  {connect}  from 'react-redux';

class Test extends Component {

  render() {
    return (
      <View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
        <Text>count:{this.props.count}</Text>
         <Button title="Increment" onPress={() => this.props.incrementCounter()}></Button>
         <Button title="Decrement" onPress={() => this.props.decrementCounter()}></Button>
      </View>
    )
}
}
const mapDispatchToProps = dispatch =>({
  incrementCounter: _ => dispatch({type:"INCREMENT_COUNTER"}),
  incrementCounter: _ => dispatch({type:"DECREMENT_COUNTER"}),
})
export default connect(state => ({ count: state.count }))(Test)

const INITIAL_STATE = {
    count: 1
}
export default (state = INITIAL_STATE, action) => {
    switch (action.type) {
        case 'COUNTER_INCREMENT': {
            return (Object.assign({}, { ...state, count: state.count + 1}))
        }
        case 'COUNTER_DECREMENT': {
            return Object.assign({},{ ...state,  count: state.count - 1 });
        }
        default: {
            return state;
        }
    }
}

import React, { Component } from 'react';
import { Platform, } from 'react-native';
import { Provider } from 'react-redux';

import { createStackNavigator} from 'react-navigation';
import Test from './src/screens/test';
import Screen2 from './src/screens/screen2';
import { createStore } from 'redux';
import reducers from './reducers';

const store = createStore(reducers);

const AppNavigator = createStackNavigator({
  test: Test,
  screen2: Screen2
}, {
    headerMode: "none"
  });

export default class App extends Component {

  render() {
    return (
      <Provider store={store}>
        <AppNavigator />
      </Provider>
    );
  }
}