Commented Unassigned: The type initializer for 'Tweetinvi.TwitterCredentials' threw an exception [2478]

// Here are the declarations:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using Tweetinvi;
using Tweetinvi.Core.Enum;
using Tweetinvi.Core.Extensions;
using Tweetinvi.Core.Interfaces;
using Tweetinvi.Core.Interfaces.Controllers;
using Tweetinvi.Core.Interfaces.DTO;
using Tweetinvi.Core.Interfaces.Models;
using Tweetinvi.Core.Interfaces.Models.Parameters;
using Tweetinvi.Core.Interfaces.oAuth;
using Tweetinvi.Core.Interfaces.Streaminvi;
using Tweetinvi.Json;
using Stream = Tweetinvi.Stream;

//The only thing I am doing is :
TwitterCredentials.SetCredentials("Access_Token", "Access_Token_Secret", "Consumer_Key", "Consumer_Secret");

I entered my "secret" values above and have checked for correctness many times. I tried regenerating them too. Keep getting error:

ERROR: The type initializer for 'Tweetinvi.TwitterCredentials' threw an exception.

Any help plz. Thanks
Comments: ** Comment from web user: rkjergaard **

I should also add that I added the project through the nuget package manager