title: console.error: "fontFamily 'Helvetica Neue' is not a system font and has not been loaded through Expo.Font.loadAsync
body: <p>In my react-native app i have added a package for event calendar <a href="https://github.com/duyluonglc/react-native-events-calendar" rel="nofollow noreferrer">Package link</a>.
  Which gives me an error message </p>
  
  <blockquote>
    <p>console.error: "fontFamily 'Helvetica Neue' is not a system font and has not been loaded through Expo.Font.loadAsync.</p>
  </blockquote>
  
  <p><strong>App.js</strong></p>
  
  <pre><code>import React from 'react';
  import { StyleSheet, Text, View, Dimensions, StatusBar } from 'react-native';
  import Header from 'react-native';
  import { WelcomeScreen } from './screens/WelcomeScreen';
  import EventCalendar from 'react-native-events-calendar';
  
  let { width } = Dimensions.get('window');
  export default class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
    events: [
      {
        start: '2017-09-06 22:30:00',
        end: '2017-09-06 23:30:00',
        title: 'Dr. Mariana Joseph',
        summary: '3412 Piedmont Rd NE, GA 3032',
        color: 'green'
      } ]
    };
   }
  _eventTapped(event) {
   alert(JSON.stringify(event));
   }
  
  render() {
  return (
    &lt;View style={{ flex: 1, marginTop: 20 }}&gt;
      &lt;EventCalendar
        eventTapped={this._eventTapped.bind(this)}
        events={this.state.events}
        width={width}
        initDate={'2017-09-07'}
        scrollToFirst
        upperCaseHeader
        uppercase
        scrollToFirst={false}
       /&gt;
      &lt;/View&gt;
      );
      }
    }
  </code></pre>
  
  <p>What is the solution for the problem?
  <a href="https://i.stack.imgur.com/ib1Tc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ib1Tc.png" alt="Error screen"></a></p>