System.IO.FileNotFoundException, Newtonsoft.Json .Net

I have .NET console application and there is a problem with newtonsoft library. When I start console application with Visual studio by clicking start button, there is no problem. Everything is good. However, If i try to run myprogram.exe under the obj/debug folder, it gives following error:

"System.IO.FileNotFoundException: 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'file or compilation, or one of its dependencies. The system can not find the specified file.File Name: 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' Location: Barcode_Form.Cloud_Form.Check_Cloud(String username, String password)"

private void button_login_Click(object sender, EventArgs e)
    {
        label_response.Text = "Baglaniyor...";
        //Make buttons not clickable until the result of login trial
        Button_status(false);
        try {
            if (textbox_password.Text != "" && textbox_id.Text != "")
            {
                //Check the cloud if the user is valid or not
                if (Cloud_Form.Check_Cloud(textbox_id.Text, textbox_password.Text) == true)
                {

                    user_id = textbox_id.Text;
                    user_pass = textbox_password.Text;
                    Network_Form network = new Network_Form();
                    Network_Form.network.Show();
                    Network_Form.network.Enabled = true;
                    this.Hide();
                    this.Enabled = false;
                    Xml_Write_Login();
                }
            }

        } 
        catch(Exception ex)
        {
            this.Enabled = true;
        }
        label_response.Text = "";
        Button_status(true);
    }

public static bool Check_Cloud(string username, string password)
    {
         try {
             string jsonstr2 = Call_Reseller_JsonStr(username, password);
             JObject outp = JObject.Parse(jsonstr2);
             string return_code = (string)outp["code"]; //check if it is successful or not
            if (return_code.Equals("200") == true)
             {
                 return true;
             }
             else {
                Console.Write("false");
                return false;
             }
         }
         catch(Exception ex)
         {
             return false;
         }
    }

it gives error check_cloud function. How can i run myprogram.exe without getting error? Thanks in advance.