Error in C # when trying to add an inherited component in ToolBox

I'm trying to create a component that inherits from a ComBox. I created the component by following the steps below, the project is available at: link

• Without any open project > File > New > Project > Class Library (Visual C #) > Name: "Custom Components"
• Delete Class1.cs
• In the "Right click" project > Add ... > Component > Component Class (Visual C # Items) > Name: "ComboBoxEx"
• In References > Add Reference ... > Search for "Forms > Check System.Windows.Forms & OK"
• In the "code" change Component by ComboBox > add% with% > in using System.Windows.Forms; under public ComboBoxEx() add InitializeComponent();
• Save and "build"
• In a WindowsFormsApplication project I right click on a tab of the "TollBox" > Choose Items ... > on the .NET Framework Components > I click Browse .. > I select "C: \ Program Files \ C # \ branches \ Repository \ HomeProducts \ Common Components \ bin \ Debug \ ComponentsProprios.dll"

This is when the message and error "There are no components in 'C: \ Programmer \ C # \ branches \ Repository \ Components \ OwnProfile \ bin \ Debug \ ComponentsProprios.dll' that is placed on the toolbox. / p>

BomboBoxEx class     using System;     using System.Collections.Generic;     using System.ComponentModel;     using System.Diagnostics;     using System.Linq;     using System.Text;     using System.Windows.Forms;

namespace ComponentesProprios
{
    public partial class ComboBoxEx : ComboBox
    {
        public ComboBoxEx()
        {
            DropDownStyle = ComboBoxStyle.DropDownList;
        }

        public ComboBoxEx(IContainer container)
        {
            container.Add(this);
        }
    }
}