npm start在create-react-app中不起作用：缺少脚本：start

Question

我试图通过执行以下操作来更新我的create-react-app版本：

  

如果您之前已经通过npm在全球范围内安装了create-react-app   安装-g create-react-app，建议您卸载该软件包   使用npm uninstall -g create-react-app确保npx始终使用   最新版本。

但是现在，当我运行npm start时，我收到一条错误消息：

missing script: start

但是在我应用程序的package.json中，我找到了启动脚本：

{
  "name": "dropzone-montessori",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.12.0",
    "react-dom": "^16.12.0",
    "react-scripts": "3.2.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

有人知道发生了什么事吗？