Some background of our application...
We can't really turn Ajax off in our application because it's entirely integral to how the application works. We use Ajax to navigate to all of the content in the application. We do make use of ResolveUpdatedControls, firing commands through the RadAjaxManager direct from the client-side code using AjaxRequest() as well as through more standard code-behind and mark-up server side configured control registrations with the RadAjaxManager. We also have a mechanism in place to prevent multiple ajax requests from being fired at the same time (from the user clicking on controls that cause ajax commands to fire).
Our application was developed on and for IIS 6, but recent developments
see our products team asking us to also support IIS 7. Other than
adding a default documents section to the web.config file we've made no changes to the application to make it run on IIS 7 (only the installation of it). This seems to
work in much the same manner as it would on IIS 6 when running in
Classic Mode and in Integrated Mode it seems to work except for handling errors.
I did know about the
http://www.telerik.com/help/aspnet/ajax/ajxcontenttype.html article you sent already actually because I read them when we were originally developing the application thanks.They helped us with the user control ID issues for dynamically loaded user controls, not using Server.Transfer and we do also make use of ResolveUpdatedControls on both client and server sides.
In the test I'm performing on our application I'm simply editing some markup to introduce a parse error. The HttpParseException is thrown in the Default.aspx page whilst dynamically loading the user control (the one with the intentional markup mistake) into a Panel. With a breakpoint in the Page_Load method of the Error page you can see it does correctly redirect to the Error page. However the application just hangs on the client-side at that point and the error console in Firefox displays the error detailed in my previous reply (Unexpected ajax response was received...).
With Ajax off I can add a markup error in the root page. For the error in the root page it does correctly then navigate to the error page without hanging. Because we use Ajax to navigate around I can't simulate an error in a dynmically loaded content control with Ajax off though.
Adding client side handlers for the RadAjaxManager OnAjaxRequestError allows me to intercept the (Unexpected ajax response was received...) error, but what can I do with it?
P.S. RadAjax assembly is 1.8.7.0.