内部连接致命错误c＃wpf

Question

我看了一遍，发现没有解决方案。我不确定导致问题的是什么，如果有人能够提供帮助，我将非常感激。我还在努力学习这门语言。

     private void SignInButton_MouseDown(object sender, MouseButtonEventArgs e)
    {
        /// Check Username and password from text box
        string username = UserName.Text;
        string password = Password.Text;




        SqlConnection myConnection = new SqlConnection(@"Data Source=46.4.90.149\MyInstance,3306;Network Library=DBMSSOCN;Initial Catalog=XXXXXX;User ID=XXXXX;Password=XXXXXX");
        try
        {
            if (myConnection.State == ConnectionState.Closed) 
                myConnection.Open();
                SqlCommand myCommand = myConnection.CreateCommand();
                myCommand.CommandText = "SELECT Username, Password FROM PlayerInfo WHERE Username =@Username AND Password =@Password";
                myCommand.Parameters.AddWithValue("@Username", username);
                myCommand.Parameters.AddWithValue("@Password", password);
                int count = Convert.ToInt32(myCommand.ExecuteScalar());
                if(count==1)
                {
                    MessageBox.Show("HELLO YOU'RE LOGGED IN");
                    myConnection.Close();
                }
            else
            {
                MessageBox.Show("Can't find account");
                myConnection.Close();
            }
        }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        finally
        {
            myConnection.Close();
        }





    }

}

}

我已经尝试了多种解决方案，然后才会抛出connection string is invalid。我设法解决了这个问题，现在我得到了internal error connection error 18.