Problems with RadEditor

[Justas]

This one is complicated even to explain. I have .aspx page in my project, which uses JSON to load some parts of page. In old version of this page, I have text area, which was replaced with fckeditor using javascript. Now, I am trying to change old fckeditor with new RAD editor.
My problem is, that when I change textarea to radeditor, I get this error :

Sys.Res is undefined

 if (!element) throw Error.argument('element', Sys.Res.createNoDom);

When editor should appear, on FF4, I see unconfigured editor, which do not responds to any of my actions, on IE8 - text area without toolbar.

Any ideas how to make this work?

[Rumen]

Hello Justas,

My suggestion is to put an Asp:ScriptManager on the page with RadEditor.
If you load the editor with Ajax then use <asp:UpdatePanel> or <telerik:RadAjaxManager> to show the control.
If you load the control with callback use RadXmlHttpPanel. Also set the RadEditor's RegisterWithScriptManager property to "false".

Best regards,
Rumen
the Telerik team