[SOLVED] Nodejs:Path must be a string without null bytes

I am trying to upload video to kaltura,but it is showing below error

Uploading file
file path /home/alok/Downloads/video.mp4
true
upload token added {"id":"######","partnerId":####,"userId":"######","status":0,"createdAt":1467038066,"updatedAt":1467038066,"objectType":"KalturaUploadToken"}





{
  "date": "Mon Jun 27 2016 20:04:16 GMT+0530 (IST)",
  "process": {
    "pid": 13534,
    "uid": 1001,
    "gid": 1001,
    "cwd": "/home/alok/Desktop/projects/myproject",
    "execPath": "/usr/local/nodejs/bin/node",
    "version": "v4.4.5",
    "argv": [
      "/usr/local/nodejs/bin/node",
      "/home/alok/Desktop/projects/myproject/app.js"
    ],
    "memoryUsage": {
      "rss": 85884928,
      "heapTotal": 77003616,
      "heapUsed": 52299120
    }
  },
  "os": {
    "loadavg": [
      1.21826171875,
      1.08837890625,
      0.89111328125
    ],
    "uptime": 31013
  },
  "trace": [
    {
      "column": 14,
      "file": "fs.js",
      "function": "nullCheck",
      "line": 94,
      "method": null,
      "native": false
    },
    {
      "column": 3,
      "file": "fs.js",
      "function": "Object.fs.openSync",
      "line": 548,
      "method": "fs.openSync",
      "native": false
    },
    {
      "column": 15,
      "file": "fs.js",
      "function": "Object.fs.readFileSync",
      "line": 397,
      "method": "fs.readFileSync",
      "native": false
    },
    {
      "column": 18,
      "file": "/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js",
      "function": "KalturaClientBase.doHttpRequest",
      "line": 433,
      "method": "doHttpRequest",
      "native": false
    },
    {
      "column": 7,
      "file": "/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js",
      "function": "KalturaClientBase.doQueue",
      "line": 336,
      "method": "doQueue",
      "native": false
    },
    {
      "column": 15,
      "file": "/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaServices.js",
      "function": "KalturaUploadTokenService.upload",
      "line": 7120,
      "method": "upload",
      "native": false
    },
    {
      "column": 47,
      "file": "/home/alok/Desktop/projects/myproject/application/services/project/projectService.js",
      "function": null,
      "line": 50,
      "method": null,
      "native": false
    },
    {
      "column": 4,
      "file": "/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js",
      "function": "",
      "line": 389,
      "method": null,
      "native": false
    },
    {
      "column": 20,
      "file": "events.js",
      "function": "emitNone",
      "line": 72,
      "method": null,
      "native": false
    },
    {
      "column": 7,
      "file": "events.js",
      "function": "IncomingMessage.emit",
      "line": 166,
      "method": "emit",
      "native": false
    },
    {
      "column": 12,
      "file": "_stream_readable.js",
      "function": "endReadableNT",
      "line": 913,
      "method": null,
      "native": false
    },
    {
      "column": 9,
      "file": "node.js",
      "function": "nextTickCallbackWith2Args",
      "line": 442,
      "method": null,
      "native": false
    },
    {
      "column": 17,
      "file": "node.js",
      "function": "process._tickCallback",
      "line": 356,
      "method": "_tickCallback",
      "native": false
    }
  ],
  "stack": [
    "Error: Path must be a string without null bytes.",
    "    at nullCheck (fs.js:94:14)",
    "    at Object.fs.openSync (fs.js:548:3)",
    "    at Object.fs.readFileSync (fs.js:397:15)",
    "    at KalturaClientBase.doHttpRequest (/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js:433:18)",
    "    at KalturaClientBase.doQueue (/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js:336:7)",
    "    at KalturaUploadTokenService.upload (/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaServices.js:7120:15)",
    "    at /home/alok/Desktop/projects/myproject/application/services/project/projectService.js:50:47",
    "    at IncomingMessage.<anonymous> (/home/alok/Desktop/projects/myproject/node_modules/kaltura/KalturaClientBase.js:389:4)",
    "    at emitNone (events.js:72:20)",
    "    at IncomingMessage.emit (events.js:166:7)",
    "    at endReadableNT (_stream_readable.js:913:12)",
    "    at nextTickCallbackWith2Args (node.js:442:9)",
    "    at process._tickCallback (node.js:356:17)"
  ],
  "level": "error",
  "message": "uncaughtException: Path must be a string without null bytes."
}

I think there is problem with fs read even file is there on specified path.

File upload on kaltura

var KalturaConstants = require('./KalturaTypes.js');
var Kaltura = require('./KalturaClient.js');

var KalturaClient = null;
var Session = null;

var pager = new Kaltura.objects.KalturaFilterPager();
pager.pageSize=10000;
pager.pageIndex=1;

var KALTURA_PARTNERID="#####";
var KALTURA_ADMINSECRET="##################";
var KALTURA_USERID="####";

var initialize = function(callback) {
    var config = new Kaltura.KalturaConfiguration(parseInt(KALTURA_PARTNERID));
    KalturaClient = new Kaltura.KalturaClient(config);
    KalturaClient.session.start(function(session) {
            KalturaClient.setKs(session);
            Session = session;
            callback();
        }, KALTURA_ADMINSECRET, KALTURA_USERID, KalturaConstants.KalturaSessionType.ADMIN,
        parseInt(KALTURA_PARTNERID), '10000000');
}

var uploadMedia = function(videoFile,userId) {

    var fs = require("fs");

    var DOWNLOAD_DIR = './downloads/';
    var fileWithPath=DOWNLOAD_DIR+videoFile;

    fs.exists(fileWithPath, function(exists) {
        if (exists) {
            fs.readFile(fileWithPath, "utf8", function(error, data) {
                var uploadToken = null;
                KalturaClient.uploadToken.add(function(token){

                    console.log("upload token added " + JSON.stringify(token));



                    KalturaClient.uploadToken.upload(function(token){

                        console.log("upload token uploaded " + JSON.stringify(token));

                        var entry = new Kaltura.objects.KalturaMediaEntry();
                        entry.name = "My Video";
                        entry.description = "My video";
                        entry.userId = userId;
                        entry.creatorId = userId;
                        entry.type = KalturaConstants.KalturaEntryType.AUTOMATIC;
                        entry.mediaType = KalturaConstants.KalturaMediaType.VIDEO;
                        entry.sourceType = KalturaConstants.KalturaSourceType.FILE;

                        KalturaClient.media.add(function(result){

                                console.log("media entry added " + JSON.stringify(result));

                                var resource = new Kaltura.objects.KalturaUploadedFileTokenResource();
                                resource.token = token.id;

                                KalturaClient.media.addContent(function(result2){
                                    //if(err) console.log('Failed to add content ' + JSON.stringify(err));
                                    console.log("media entry updated with content " + JSON.stringify(result2));
                                }, result.id, resource);


                        },entry);

                    },token.id,data);

                }, uploadToken);
            });
        }
    });

}

initialize(function () {
    console.log('Uploading file');
    uploadMedia('main_OUTPUT.tmp.mp4',1901);
});

Please help, i am new to node.js.

Thanks