To reproduce:

Add a RadCollapsiblePanel to a form and set its IsExpanded property using the property grid at design time. Start the application and you will notice that the inner container is hiding the header and makes it unusable.

Workaround:

Use the following class, by passing it all your forms which have a RadCollapsiblePanel it will hide the inner container when each loads:



public class RadCollapsiblePanelIsExpandedFixer
{
    private Dictionary<Form, List<RadCollapsiblePanel>> panels = new Dictionary<Form, List<RadCollapsiblePanel>>();


    public RadCollapsiblePanelIsExpandedFixer(params Form[] forms)
    {
        foreach (Form form in forms)
        {
            foreach (Control control in form.Controls)
            {
                RadCollapsiblePanel panel = control as RadCollapsiblePanel;
                if (panel != null)
                {
                    if (!panels.ContainsKey(form))
                    {
                        panels[form] = new List<RadCollapsiblePanel>();
                    }


                    panels[form].Add(panel);
                    form.Load += form_Load;
                }
            }
        }
    }


    void form_Load(object sender, EventArgs e)
    {
        Form loadedForm = sender as Form;
        foreach (RadCollapsiblePanel panel in panels[loadedForm])
        {
            panel.ControlsContainer.Size = Size.Empty;
        }


        loadedForm.Load -= form_Load;
        panels.Remove(loadedForm);
    }
}