Element type is invalid: expected a string (for built-in components) on react-native

```
import React from 'react'
import { Text, View, ScrollView, AppRegistry, } from 'react-native'
import { Link, nativeHistory, Route, Router, withRouter, StackRoute, } from 'react-router-native'

const Master = (props) => (

{props.children}

)

const Home = () => {
const Menu = ({ page,text }) => (



)

return (







)
}

const MenuPage = withRouter((props) => {
const { routeParams } = props
const page = routeParams.page
const text = routeParams.text

return(
This will be {text}
)
})

const routes = (






)

AppRegistry.registerComponent('Last', () => routes)
```