Error: Cannot find module './lib/mediaType'"

successful login authentication

module.js:540
throw err;
^

Error: Cannot find module './lib/mediaType'
    at Function.Module._resolveFilename (module.js:538:15)
    at Function.Module._load (module.js:468:25)
    at Module.require (module.js:587:17)
    at require (internal/module.js:11:18)

    at loadModule (D:GitHubjs_exmplsauthenticationnode_modulesnegotiatorindex.js:114:16)

    at Negotiator.mediaTypes (D:GitHubjs_exmplsauthenticationnode_modulesnegotiatorindex.js:76:29)

    at Accepts.type.Accepts.types (D:GitHubjs_exmplsauthenticationnode_modulesacceptsindex.js:105:33)

    at IncomingMessage.req.accepts (D:GitHubjs_exmplsauthenticationnode_modulesexpresslibrequest.js:134:23)

    at ServerResponse.res.format (D:GitHubjs_exmplsauthenticationnode_modulesexpresslibresponse.js:627:11)

    at ServerResponse.redirect (D:GitHubjs_exmplsauthenticationnode_modulesexpresslibresponse.js:888:8)

    at D:GitHubjs_exmplsauthenticationapp.js:113:6

    at D:GitHubjs_exmplsauthenticationnode_modulespassportlibmiddlewareauthenticate.js:249:29

    at D:GitHubjs_exmplsauthenticationnode_modulespassportlibhttprequest.js:51:48

    at D:GitHubjs_exmplsauthenticationnode_modulespassportlibsessionmanager.js:16:14

    at pass (D:GitHubjs_exmplsauthenticationnode_modulespassportlibauthenticator.js:297:14)

    at Authenticator.serializeUser (D:GitHubjs_exmplsauthenticationnode_modulespassportlibauthenticator.js:299:5)

    at SessionManager.logIn (D:GitHubjs_exmplsauthenticationnode_modulespassportlibsessionmanager.js:14:8)

    at IncomingMessage.req.login.req.logIn (D:GitHubjs_exmplsauthenticationnode_modulespassportlibhttprequest.js
:50:33)

    at Strategy.strategy.success (D:GitHubjs_exmplsauthenticationnode_modulespassportlibmiddlewareauthenticate.j
s:248:13)

    at verified (D:GitHubjs_exmplsauthenticationnode_modulespassport-locallibstrategy.js:83:10)

    at PBKDF2.ondone (D:GitHubjs_exmplsauthenticationnode_modulespassport-local-mongooselibauthenticate.js:48:12))

"var mediaType = require('media-type');"

var http = require('http');

var mongoose = require('mongoose');

var mongodb=require('mongodb');

var express=require('express');

var csv = require('csv');

var bodyParser= require('body-parser');

var fs = require('fs');

var path=require('path');

var assert= require('assert');

var User= require("./models/user.js");

var passport= require('passport');

var mediaType = require('media-type');

var LocalStrategy= require('passport-local');

var passportLocalMongoose= require('passport-local-mongoose');

var mongoClient=require('mongoose');

var app = express();

var Schema = mongoose.Schema;

.

.

 app.get('/login', function (req, res) {

 res.render('login' );

})
.

.


app.post("/login",function(req,res,err){

    if (err) {console.log(err); };//else not needed render is end

    passport.authenticate("local")(req,res,function(){

       console.log("successful login authentication");

    res.redirect("./views/friends.ejs");

    });

    })