"The syntax of the command is incorrect" error

[ajitgoel]

I get a "The syntax of the command is incorrect". any ideas what i am doing wrong?

wpshout-react-quiz@1.0.0 concat:js C:\wamp64\www\wordpress\wp-content\plugins\wpshout-react-quiz > mkdir -p dist/js && concat -o dist/js/scripts.js 1.js 2.js The syntax of the command is incorrect.

{
  "name": "wpshout-react-quiz",
  "version": "1.0.0",
  "description": "",
  "main": "wpshout-react-quiz.js",
  "dependencies": {
    "concat": "^1.0.3",
    "npm-run-all": "^4.1.2",
    "onchange": "^3.3.0",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-image-lightbox": "^4.5.0",
    "react-slick": "^0.19.0",
    "uglify": "^0.1.5",
    "watch": "^1.0.2"
  },
  "devDependencies": {},
  "scripts": {
    "concat:js": "mkdir -p dist/js && concat -o dist/js/scripts.js 1.js 2.js",
    "concat": "npm run concat:js",
    "uglify": "uglifyjs -o dist/js/scripts.min.js dist/js/scripts.js",
    "build:js": "npm run concat:js && npm run uglify",
    "build": "npm run build:js",
    "watch": "watch 'npm run build' node_modules/react/umd/ node_modules/react-dom/umd/ node_modules/react-slick/lib/mixins/ node_modules/react-slick/lib/utils/ node_modules/react-slick/lib/ node_modules/react-slick/dist/"
  },
  "author": "",
  "license": "ISC"
}

[Neospiro]

I know this issue is old, but if someone have a similar problem, here is a solution : look at your spaces !

I found " " U+00A0 | NO-BREAK SPACE in my command lines. I think it comes from an example command about this module, somewhere on internet.