title: How can i resolve this error in React+Material UI
body: <p>I'm getting the following error while tried to run the application in Mac and Ubuntu. But it runs without any errors in Windows platform. How can i resolve this. Is there any platform specific code in Material UI beta version(v1.0.0-beta.46). I have used the withStyles component, which is an higher order component of material ui.</p>
  
  <p>Error:</p>
  
  <pre><code>/node_modules/material-ui/styles/withStyles.js
  Module not found: Can't resolve '@babel/runtime/core-js/map'
  </code></pre>
  
  <p>The below is my code</p>
  
  <pre><code>import React from 'react';    
  import PropTypes from 'prop-types';     
  import withStyles from 'material-ui/styles';    
  import AppBar from 'material-ui/AppBar';    
  import Toolbar from 'material-ui/Toolbar';    
  import Typography from 'material-ui/Typography';    
  import Button from 'material-ui/Button';    
  import Avatar from 'material-ui/Avatar';    
  import classNames from 'classnames';    
  import AppIcon from '../../assets/img/myAppIcon.png';
  
  const styles = theme =&gt; ({                
      root: {
          flexGrow: 1,
      },
      flex: {
          flex: 1,
      },
      menuButton: {
              marginLeft: -12,
              marginRight: 20,
      },
      loginButton:{
              alignContent: "flex-end"
      },
      avatar: {
              margin: 10,
      },
      toolbar: {
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'flex-end',
          padding: '0 8px',
          ...theme.mixins.toolbar,
      },
      content: {
          flexGrow: 1,
          backgroundColor: theme.palette.background.default,
          padding: theme.spacing.unit * 3,
      },
  });
  
  // Here is my functional component which renders the AppBar with login button at the right hand side.
  
  function Layout(props) {
    const { classes } = props;
    return (
      &lt;div className={classes.root}&gt;
        &lt;AppBar
            position="absolute"
            className={classNames(classes.appBar)}
          &gt;
            &lt;Toolbar&gt;                    
              &lt;Avatar src={AppIcon} className={classes.avatar} /&gt;
              &lt;Typography variant="title" color="inherit" noWrap&gt;
                MyApp
              &lt;/Typography&gt;
              &lt;Typography variant="title" color="inherit" noWrap className={classes.flex} /&gt;
              &lt;Button color="inherit"&gt;Login&lt;/Button&gt;
            &lt;/Toolbar&gt;          
          &lt;/AppBar&gt;  
          &lt;main className={classes.content}&gt;
              &lt;div className={classes.toolbar} /&gt;
              {props.children}
          &lt;/main&gt;        
      &lt;/div&gt;
    );
  }
  
  Layout.propTypes = {
    classes: PropTypes.object.isRequired,
    theme: PropTypes.object.isRequired,
  };
  
  //Here I'm getting an error on executing this
  export default withStyles(styles, { withTheme: true })(Layout);
  </code></pre>