使用EXT4报错！大神快来看~求解决

使用EXT4报错！大神快来看~求解决 - Web 开发 / Ajax
学习搭建ext4的MVC，报错~
错误是：例外被抛出且未被接住 ext-all-debug.js 
我的代码是：
app:

Java code

Ext.application({    name:'AM',    appFolder:'js',    controllers:["Users"],    launch: function () {        Ext.create('Ext.container.Viewport', {            layout: 'fit',            items: [{                xtype: 'userlist'            }]        });     }});

Java code

Ext.define('AM.controller.Users', {    extend: 'Ext.app.Controller',    views: [        'List',        'Edit'    ],    stores:[        "Users"    ],    models:["User"],    init: function () {        this.control({            'userlist': {                itemdblclick: this.editUser            }        });    },    editUser: function(grid, record) {        console.log('Double clicked on ' + record.get('name'));    }});

Java code

Ext.define('AM.model.User', {    extend: 'Ext.data.Model',    fields: ['name', 'email']})

Java code

Ext.define('AM.store.Users', {    extend: 'Ext.data.Store',    model: 'AM.model.User',    data: [        { name: 'Ed', email: 'ed@sencha.com' },        { name: 'Tommy', email: 'tommy@sencha.com' }    ]});

Java code

Ext.define('AM.view.List', {    extend: 'Ext.grid.Panel',    alias: 'widget.userlist',    title: 'All Users',    initComponent: function () {        this.store = "Users";        this.columns = [            { header: 'Name', dataIndex: 'name', flex: 1 },            { header: 'Email', dataIndex: 'email', flex: 1 }        ];        this.callParent(arguments);    }});