Inherited UserControl and VS designer problem

Hello in my code I have one parent class as follows:

public partial class MyControl : UserControl
{
  protected Dictionary<string, object> settings;

  public abstract Dictionary<string, object> Settings
  {
    get;
    set;
  }

  public MyControl()
  {
    InitializeComponent();
  }
}

And now I need to create several controls inherited from MyControl and I need to override Settings property. But after adding new UserControl and overwriting UserControl to MyControl (in class inheritance), the designer stop working...

Any help?