[Solved] npm start error with create-react-app

Sometimes when we run this command we get this type of error - 

> react-scripts start

sh: react-scripts: command not found

npm ERR! Darwin 16.0.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "start"
npm ERR! node v6.7.0
npm ERR! npm  v3.10.3
npm ERR! file sh
npm ERR! code ELIFECYCLE
npm ERR! errno ENOENT
npm ERR! syscall spawn
npm ERR! UpScore@0.6.0 start: `react-scripts start`
npm ERR! spawn ENOENT
npm ERR!
npm ERR! Failed at the UpScore@0.6.0 start script 'react-scripts start'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the UpScore package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     react-scripts start
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs UpScore
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls UpScore
npm ERR! There is likely additional logging output above.

package.json

{
  "name": "UpScore",
  "version": "0.6.0",
  "private": true,
  "devDependencies": {
    "react-addons-test-utils": "^15.3.1",
    "react-scripts": "0.4.1",
    "react-test-renderer": "^15.3.1",
    "redux-logger": "^2.6.1"
  },
  "dependencies": {
    "@yoshokatana/medium-button": "^1.1.0",
    "axios": "^0.14.0",
    "bcrypt": "^0.8.7",
    "bcrypt-nodejs": "0.0.3",
    "bcryptjs": "^2.3.0",
    "body-parser": "^1.15.2",
    "connect-flash": "^0.1.1",
    "cookie-parser": "^1.4.3",
    "draft-js": "^0.8.1",
    "draft-js-editor": "^1.7.2",
    "draft-js-export-html": "^0.4.0",
    "ejs": "^2.5.2",
    "email-verification": "^0.4.5",
    "express": "^4.14.0",
    "express-session": "^1.14.1",
    "flexboxgrid": "^6.3.1",
    "highlight.js": "^9.6.0",
    "immutable": "^3.8.1",
    "katex": "^0.6.0",
    "lodash": "^4.15.0",
    "markdown-it-mathjax": "^1.0.3",
    "material-ui": "^0.15.4",
    "medium-editor": "^5.22.0",
    "minutes-seconds-milliseconds": "^1.0.3",
    "moment": "^2.15.0",
    "moment-duration-format": "^1.3.0",
    "mongod": "^1.3.0",
    "mongodb": "^2.2.9",
    "mongoose": "^4.6.0",
    "monk": "^3.1.2",
    "morgan": "^1.7.0",
    "normalize.css": "^3.0.3",
    "passport": "^0.3.2",
    "passport-local": "^1.0.0",
    "react": "^15.3.1",
    "react-dom": "^15.3.1",
    "react-markdown": "^2.4.2",
    "react-medium-editor": "^1.8.1",
    "react-redux": "^4.4.5",
    "react-redux-form": "^0.14.5",
    "react-rich-markdown": "^1.0.1",
    "react-router": "^2.7.0",
    "react-router-redux": "^4.0.5",
    "react-tap-event-plugin": "^1.0.0",
    "react-tinymce": "^0.5.1",
    "redux": "^3.6.0",
    "redux-form": "^6.0.5",
    "redux-form-material-ui": "^4.0.1",
    "redux-promise-middleware": "^4.0.0",
    "redux-thunk": "^2.1.0",
    "reselect": "^2.5.3",
    "screenfull": "^3.0.2"
  },
  "scripts": {
    "start": "react-scripts start",
    "start:prod": "pushstate-server build",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject",
    "server": "cd client/api && pm2 start server.js --watch",
    "proxy": "http://128.199.139.144:3000"
  },
  "eslintConfig": {
    "extends": "./node_modules/react-scripts/config/eslint.js"
  }
}

Solution:

You should not install react-scripts globally.

You also don't need ./node_modules/react-scripts/bin/ in package.json as this answer implies.

if you see this:

npm ERR! UpScore@0.6.0 start: `react-scripts start`
npm ERR! spawn ENOENT

It just means something went wrong when dependencies were installed for the first time.

I suggest to do these steps:

npm install -g npm@latest

to update npm because it is sometimes buggy.

rm -rf node_modules

to remove the existing modules.

npm install

to re-install the project dependencies.