underfined is not an object(evaluating 'viewproptypes.style')

代码都没动过，之前可以跑起来 现在就成这样了 会是什么原因？

昨天还可以运行打开，welcomepage界面然后两秒后 跳转homepage界面，现在啥都没有了。

welcomepage代码如下

import React, {
	Component
} from 'react';
import {
	StyleSheet,
	Text,
	View,
	Navigator
} from 'react-native';
import NavigationBar from '../common/NavigationBar'
import HomePage from './HomePage'
// import ListViewTest from './ListViewTest'
export default class WelcomePage extends Component {
	componentDidMount() {
		this.timer = setTimeout(() => {
			this.props.navigator.resetTo({
				component: HomePage,
			})
		}, 2000)
	}
	componentWillUnmount() {
		this.timer && clearTimeout(this.timer);
	}
	render() {
		return <View >
			
			{/*
			<NavigationBar 
			title={'欢迎'}/>
			
			*/}
		<Text>欢迎</Text> 
		
			</View>
	}
}

package.json文件内容如下

{
  "name": "imooc_gp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest"
  },
  "dependencies": {
    "react": "15.4.1",
    "react-native": "0.39.2",
    "react-native-easy-toast": "^1.0.6",
    "react-native-scrollable-tab-view": "^0.6.6",
    "react-native-tab-navigator": "^0.3.3"
  },
  "devDependencies": {
    "babel-jest": "17.0.2",
    "babel-preset-react-native": "1.9.0",
    "jest": "17.0.3",
    "react-test-renderer": "15.4.1"
  },
  "jest": {
    "preset": "react-native"
  }
}