C# Error: 'Class' is inaccessible due to protection level
<p>I Have this error: 'CLGDMFeed.Dal.DataManager' is inaccessible due to protection level.
And I have no Idea why i get this.</p>

<p>Tis is my class.</p>

<pre><code>using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CLGDMFeed.Bol;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;


namespace CLGDMFeed.Dal
{
    public static class DataManager
    {

        #region Methods
        public static void SerializeFeed(string sFileName, Feed feed)
        {
            try
            {
                using (Stream stream = File.Open(sFileName, FileMode.Create))
                {
                    BinaryFormatter binform = new BinaryFormatter();
                    binform.Serialize(stream, feed);
                    stream.Close();
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message, ex);
            }
        }

        public static Feed DeSerializeFeed(string sFileName)
        {
            Feed feed;
            try
            {
                using (Stream stream = File.Open(sFileName, FileMode.Open))
                {
                    BinaryFormatter binform = new BinaryFormatter();
                    feed = (Feed)binform.Deserialize(stream);
                    stream.Close();
                }
                return feed;
            }

            catch (Exception ex)
            {
                throw new Exception(ex.Message, ex);
            }
        }

        public static void SerializeIListFeed(string sFileName, IList&lt;Feed&gt; list)
        {
            try
            {
                using (Stream stream = File.Open(sFileName, FileMode.Create))
                {
                    BinaryFormatter bf = new BinaryFormatter();
                    bf.Serialize(stream, list);
                    stream.Close();
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message, ex);
            }
        }

        public static IList&lt;Feed&gt; DeSerializeIListFeed(string sFileName)
        {
            IList&lt;Feed&gt; list;
            try
            {
                using (Stream stream = File.Open(sFileName, FileMode.Open))
                {
                    BinaryFormatter bf = new BinaryFormatter();
                    list = (IList&lt;Feed&gt;)bf.Deserialize(stream);
                    stream.Close();
                }
                return list;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message, ex);
            }
        }





                #endregion
    }
}
</code></pre>

<p>This is my form</p>

<pre><code>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 CLGDMFeed.Dal;
using CLGDMFeed.Bol;


namespace ViewerGDMFeed
{
    public partial class Viewer : Form
    {
        //Lijst van object Deserializeren van een bestand zodat je ermee kan werken
        IList&lt;Feed&gt; ListFeeds = DataManager.DeSerializeIListFeed("C:\\Documents and Settings\\sam\\Bureaublad\\Listfeeds.lfds");

        public Viewer()
        {
            InitializeComponent();

            //De namen van de feeds toevoegen aan je combobox
            foreach (Feed feed in ListFeeds)
            {
                comboBox.Items.Add(feed.STitle);
            }

        }

        private void comboBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            //Overlopen welke feed uit je lijst overeenkomt met de gekozen feed uit combox
            foreach (Feed feed in ListFeeds)
            { 

                if (comboBox.SelectedText == feed.STitle)
                {
                    //De labels invullen met de juiste data
                    ViewerLabelTitle.Text = feed.STitle;
                    //...
                }
            }
        }

    }
}
</code></pre>

<p>Sorry for all the code</p>

<p>Does anyone kno how to solve tis problem?
Thanks</p>

<hr>

<p>I have rebuild the classliberary and the error is gone.</p>

<p>But I have a new error: Metadata file 'C:\Documents and Settings\sam\Bureaublad\Herexamen programmeren\WindowsFormsApplication1\CLGDMFeed\bin\Debug\CLGDMFeed.dll' could not be found</p>
