Cannot read property 'displayName' of undefined

I'm getting this error when I try to run the vanilla example in my own app

``` jsx
import NavigationBar from 'react-native-navbar'

...

render () {
const rightButtonConfig = {
title: 'Next',
handler: () => {
alert('hello!')
}
}
const titleConfig = {
title: 'Hello, world',
}
return (



Dashboard Screen


)
}
```


Has anyone seen this before?

Start by reproducing the error from the vanilla example using the shown NavigationBar import and render configuration. Trace where the undefined value is accessed during rendering, then verify the issue's cause and confirm that the example runs without the displayName error.

Written by the indexing model from the issue text.