Created Unassigned: 400 error Bad Request [2072]

Please help. I am new to this api via c# and i dont understand what is going wrong.
What am i missing to create a simple tweet?


using System;
using System.Collections.Generic;
using System.Configuration;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using Tweetinvi;
using Tweetinvi.Json;
using TweetinviCore.Enum;
using TweetinviCore.Extensions;
using TweetinviCore.Interfaces;
using TweetinviCore.Interfaces.Controllers;
using TweetinviCore.Interfaces.DTO;
using TweetinviCore.Interfaces.Models;
using TweetinviCore.Interfaces.oAuth;
using TweetinviCore.Interfaces.Streaminvi;
using Stream = Tweetinvi.Stream;

namespace ConsoleApplication3
{
class Program
{
static void Main(string[] args)
{


var credentials = TwitterCredentials.CreateCredentials(
ConfigurationManager.AppSettings["token_AccessToken"],
ConfigurationManager.AppSettings["token_AccessTokenSecret"],
ConfigurationManager.AppSettings["token_ConsumerKey"],
ConfigurationManager.AppSettings["token_ConsumerSecret"]);

TwitterCredentials.Credentials = credentials;

// Using Static Tweet class
var tweet = Tweet.CreateTweet("Hello");
Tweet.PublishTweet(tweet);

var exceptionStatusCode = ExceptionHandler.GetLastException().StatusCode;
var exceptionDescription = ExceptionHandler.GetLastException().TwitterDescription;
var exceptionDetails = ExceptionHandler.GetLastException().TwitterExceptionInfos.First().Message;

Console.WriteLine(exceptionStatusCode);
Console.WriteLine(exceptionDescription);
Console.WriteLine(exceptionDetails);
Console.WriteLine(@"END");
Console.ReadLine();
}
}
}


console gives
error code: 400
error decription: bad request
error details: bad authentication data