ingig,
Did you ever get a solution to this? I am doing something similar, where I want to hide one Editor and show another using a callback, but in order to do that I need to render the control to an htmlwriter, but get the same error:
exception.ToString() "System.Web.HttpUnhandledException: Exception of type System.Web.HttpUnhandledException was thrown. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at CuteEditor.a.a(ContextMenuEnable A_0, String A_1)
at CuteEditor.a.e(HtmlTextWriter A_0)
at CuteEditor.a.j(HtmlTextWriter A_0)
at CuteEditor.a.i(HtmlTextWriter A_0)
at CuteEditor.a.k(HtmlTextWriter A_0)
at CuteEditor.Editor.Render(HtmlTextWriter writer)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
.........
Any help anyone could give me would be great.
Cheers,
Tom.