problem description

antdmenuSubMenu
SubMenu 
 Menu.ItemSubMenu
 Menu{}js

    SubPopupMenu.js:359 Uncaught TypeError: Cannot read property "mode" of undefined
    index.js:1446 The above error occurred in the <SubPopupMenu> component:
    react-dom.development.js:20781 Uncaught TypeError: Cannot read property "mode" of undefined

the environmental background of the problems and what methods you have tried

the project is created using react scaffolding-typescript, and is trying to use the development of ts+react

  "dependencies": {
    "@types/jest": "24.0.0",
    "@types/node": "10.12.24",
    "@types/react": "16.8.2",
    "@types/react-dom": "16.8.0",
    "antd": "^3.13.2",
    "axios": "^0.18.0",
    "babel-plugin-import": "^1.11.0",
    "node-sass": "^4.11.0",
    "react": "^16.8.1",
    "react-dom": "^16.8.1",
    "react-router-dom": "^4.3.1",
    "react-scripts": "2.1.4",
    "typescript": "3.3.3"
  }

related codes

/ / Please paste the code text below (do not replace the code with pictures)

 render() {
        let MenuConfig= [
            {
                title: "",
                key: "/admin/home"
            },
            {
                title: "2",
                key: "/admin/home2"
            },
            {
                title: "3",
                key: "/admin/home3",
                children: [
                    {
                        title: "",
                        key: "/admin/home4"
                    }
                ]
            }
        ]
        return (
            <div>
                <Menu mode="vertical" theme="dark" >
                    {MenuConfig.map(item =>
                        item.children ?
                            <SubMenu title={item.title} key={item.key}> {this.renderMenu(item.children)}</SubMenu>
                            :
                            <Menu.Item title={item.title} key={item.key}>{item.title}</Menu.Item>
                    )}
                </Menu>
            </div>
        )
    }

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