Vad gör jag för fel? C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;

namespace TestForm2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            FillData();
        }

        void FillData()
        {
            // 1.
            // Open Connection
            using (SqlCeConnection c = new SqlCeConnection(
                Properties.Settings.Default.BlueprintDBConnectionString))
            {
                c.Open();
                // 2.
                // Create new DataAdapter
                using (SqlCeDataAdapter a = new SqlCeDataAdapter(
                    "SELECT * FROM BlueprintIndex", c))
                {
                    // 3.
                    // Use DataAdapter to fill DataTable
                    DataTable t = new DataTable();
                    a.Fill(t);
                    // 4.
                    // Render data onto the screen
                    dataGridView1.DataSource = t;
                }
            }
        }
    }
}