reactjs - Element type is invalid: got: undefined -

import * react 'react'; import * reactdom 'react-dom'; import {jumbotron} 'ui-library'; import registerserviceworker './registerserviceworker'; import './index.css';  reactdom.render(   <jumbotron />,   document.getelementbyid('root') htmlelement ); registerserviceworker(); 

this index.ts

import * react 'react';  class jumbotron extends react.component<{},{}>{     constructor(props:{},context: {}){         super(props,context)     }     render(){         return (<h1>hello, world </h1>);     } }  export default jumbotron 

this topheader defined in library

this index.ts of ui-library

export {default jumbotron} './jumbotron'; export {default topheader} './topheader'; 

i getting following error react

element type invalid: expected string (for built-in components) or class/function (for composite components) got: undefined.

any appreciated.

change ui-library file to:

import jumbotron './jumbotron'; import topheader './topheader';  export { jumbotron } export { topheader } 

also looks importing ui-library npm package. verify file path importing correct?

import {jumbotron} 'ui-library'; 

i expect like:

import {jumbotron} './ui-library';