HEROKU Disconnected from log stream. There may be events happening that you do not see here! Attempting to reconnect

I pushed a project on Heroku and check and then go to

More > View logs

This is my code:

var admin = require("firebase-admin");
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var serviceAccount = require("./serviceAccountKey.json");

app.use(bodyParser.urlencoded({ extended: true }));    

console.log("HELLO WORLD");

and display

2017-05-18T13:31:12.548867+00:00 app[api]: Release v15 created by user mail@mail.com
2017-05-18T13:31:12.548867+00:00 app[api]: Deploy a13cfedb by user mail@mail.com
2017-05-18T13:30:56.000000+00:00 app[api]: Build succeeded
2017-05-18T13:35:10.000000+00:00 app[api]: Build started by user mail@mail.com
2017-05-18T13:35:26.442732+00:00 app[api]: Deploy 2beqer61 by user mail@mail.com
2017-05-18T13:35:26.442732+00:00 app[api]: Release v16 created by user mail@mail.com
2017-05-18T13:35:10.000000+00:00 app[api]: Build succeeded
2017-05-18T13:57:04.000000+00:00 app[api]: Build started by user mail@mail.com
2017-05-18T13:57:21.455262+00:00 app[api]: Deploy 31d134 by user mail@mail.com
2017-05-18T13:57:21.455262+00:00 app[api]: Release v17 created by user mail@mail.com
2017-05-18T13:57:04.000000+00:00 app[api]: Build succeeded
Disconnected from log stream. There may be events happening that you do not see here! Attempting to reconnect...

I tried to google the error but it seem that anybody else got the same error as me. Does anyone can explain me how to fix it ?

via S7_0