react+redux報(bào)錯(cuò)問題

在react+redux項(xiàng)目中，一直下面這個(gè)錯(cuò)：

   入口代碼如下：
   
    import React, {Component} from 'react';
    import {render} from 'react-dom';
    import { createStore , combineReducers} from 'redux';
    import { Provider, applyMiddleware } from 'react-redux';
    import { createLogger } from 'redux-logger';
    import thunk from 'redux-thunk';
    
    const middleware = [ thunk ];
    if (process.env.NODE_ENV !== 'production') {
        middleware.push(createLogger());
    }
    
    import LoginContainer from '../component/LoginContainer.js';
    
    import login from '../redux/reducer/login.js'
    
    let reducers = combineReducers({
        login
    })
    
    const store = createStore(
        reducers,
        applyMiddleware(...middleware)
    )
    
    render((
        <Provider store={store}>
    
            <LoginContainer />
    
        </Provider>
    ), document.getElementById('root'));
    
    
    這個(gè)是什么情況啊