I have read this thread from the start and I have a few suggestions for you to try.
First, install a HTTP debugging proxy (Fiddler for IE or Firebug for Firefox) and check what happens with the Telerik.Web.UI.DialogHandler.aspx request. By default, the editor is configured to make a request for the Telerik.Web.UI.DialogHandler.aspx file in the same folder as the web form, where the editor is. For example, let's assume you have a page http://myserver/application/folder/WebForm.aspx
which has a RadEditor control. If you open a dialog, the editor will make a request for http://myserver/application/folder/Telerik.Web.UI.DialogHandler.aspx
. If possible, open a formal support ticket and send us the site URL and details on how to reach the editor control, so we can test the behavior from here.
This dialog request is handled by the httpHandler entry you have in the web application's Web.config file. If there is a different handler or HTTP module, which is placed before our own dialog handler, it might alter the request - e.g. redirect it to the home page. Also, see if there is a second Web.config file in your application, which clears the HTTP handlers. If this is the case, then the request for the dialog handler will cause a 404 not found error.
If nothing else works, you can try overriding the default editor behavior and creating your own dialog handler file. Here is how to do that:
1. Set the editor's DialogHandlerUrl property to "~/Telerik.Web.UI.DialogHandler.aspx".
2. Create a new file called Telerik.Web.UI.DialogHandler.aspx in the root of your web application
3. Put the following line in the newly created file:
<%@ Page Language="C#" Inherits="Telerik.Web.UI.DialogHandler, Telerik.Web.UI, Culture=neutral, PublicKeyToken=121fae78165ba3d4" %>
Next time you try to open a dialog from the editor, it will look specifically for the Telerik.Web.UI.DialogHandler.aspx file in the application root folder and the Web.config httpHandlers entry will have no effect.
In summary, here are the three suggestions I gave you:
1. Use Fiddler to check what happens with the Telerik.Web.UI.DialogHandler.aspx request.
2. Check your web.config files /ask GoDaddy/ for any 3rd party http modules that could interfere with the request.
3. Try creating a physical dialog handler file in your application
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.