New Post: Posting Tweets(Beginner)

As i am totally new to the twitter api scene, i did some research and started on using Tweetinvi API. So currently my progress is here

private void Form5_Load(object sender, EventArgs e)
        {
            TwitterCredentials.SetCredentials
                ( Access_Token, Access_Token_Secret, Consumer_Key, Consumer_Secret );
            TwitterCredentials.ApplicationCredentials = TwitterCredentials.CreateCredentials
                (Access_Token, Access_Token_Secret, Consumer_Key, Consumer_Secret);
            var user = User.GetLoggedUser(); 
        }

        private void updateButton_Click(object sender, EventArgs e)
        {

            var tweet = Tweet.PublishTweet(mainRichTextBox.Text);
        }

with the credentials set in a private string.

My error is that when i press the update button, VS2010 throws the error "The type initializer for 'Tweetinvi.Tweet' threw an exception."

any direction to the proper path would be much appreciated