Great solution to the "specified cast is invalid" problem while binding an asp.net CheckBox control inside of an Telerik RadGrid FormTemplate. ASP.NET Classic Controls - Grid Forum - asp:Checkbox in FormTemplate. "Specified Cast is Invalid" . From Fabian Schulz: I ran across the same problem and have created a simple solution, which is most easy to use: Create a usercontrol with the following code: myCheckbox.ascx: myCheckbox.ascx.cs: public partial class Controls_myCheckBox : System.Web.UI.UserControl { private bool m_checked = false; public object Checked { get { return m_checked; } set { if (value.GetType() == DBNull.Value.GetType()) m_checked = false; else if (value == null) m_checked = false; else if (value.GetType() == typeof(bool)) m_checked = (bool)value; else m_checked = false; } } protected void Page_Load(object sender, EventArgs e) { m_checked = CheckBox1.Checked; } protected void Page_PreRender() { CheckBox1.Ch...