Debugging Error for Node app

Question

I recently cloned a web application (Node.js/Express + React), which I am trying to debug.

I have tried using the node-debugger and also tried to use my WebStorm configuration to run the application in debug mode.

The error I see in both the cases is the following:

Unhandled rejection SyntaxError: Unexpected reserved word
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:373:25)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Module.require (module.js:353:17)
    at require (internal/module.js:12:17)

Here is a part of script section of my package.json

  "main": "server.js",
  "scripts": {
    "start": "webpack && babel-node server.js",
    "test": "grunt test",
    "build": "grunt build",
    "all": "npm run build && npm run test"
  },

I am unsure what this error is and how to get the debugger running.