The remote endpoint could not be called, or the response it returned was invalid. -> Error in Amazon Dev Portal

createFile.js

module.exports = function createFile (test, callback) {
  callback(test)
}

CreateFileFunction.js

var fs = require('fs')
var authorize = require('./google/authorize.js')
var clientSecretsFile = 'client_secret.json'
var createFile = ('./google/createFile.js')

module.exports = CreateFileFunction

function CreateFileFunction (intent, session, response) {
  var accessToken = JSON.stringify(session.user.accessToken)
  fs.readFile(clientSecretsFile.toString(), function processClientSecrets (err, content) {
    if (err) {
      console.log('Error Loading client secret file: ' + err)
      var secretsError = 'There was an issue reaching the skill'
      response.tell(secretsError)
      return
    } else {
      authorize(JSON.parse(content), accessToken, function (err, oauthClient) {
        if (err) {
          var noOauth = 'We failed getting an oauthClient'
          response.tell(noOauth)
          return err
        }
        var test = 'test'
        createFile(test, function (name) {
          response.tell(name)
        })
      })
    }
  })
}

I have tested the CreateFileFunction and it runs successfully (meaning outputs a message to alexa) right after I call the authorize function. Once I call createFile, it seems to throw this error: The remote endpoint could not be called, or the response it returned was invalid. The purpose of creatFile this point is just to take in string test call the callback function and have alexa just respond saying test. Any idea why it is failing on that function?