Error Exception no SDK license in C# programming?

i code a programming but error is: "System.Runtime.InteropServices.COMException occurred HResult=-2147221503 Message=no SDK license Source=Roboform.RfIdentity.1 ErrorCode=-2147221503 StackTrace: at ROBOFORMLib.IRfIdentity.Create(String sCountry) at ungdung.Form1.button1_Click(Object sender, EventArgs e)....