Problem:
Was getting this error with IIS7 and Telerik Dialog control. Which says that “Web.config registration missing! The Telerik dialogs require a HttpHandler registration in the web.config file.”
Solution:
Telerik guys says “When a web site is running under IIS7 Integrated mode, the web server searches the HttpHandler registrations under the <system.webServer> configuration section instead of the standard <system.web> configuration section of the application configuration file.”.
All you need to do to manually register the HttpHandler for the IIS7 Integrated mode is copy the Telerik HttpHandler to the <handlers> section of the <system.webServer> section group, delete the validate attribute and give it a name, e.g.
<system.webServer> <handlers> … <add name="Telerik.Web.UI.DialogHandler" path="Telerik.Web.UI.DialogHandler.aspx" verb="*" type="Telerik.Web.UI.DialogHandler, Telerik.Web.UI" /> … </handlers> </system.webServer>
Thanks to : http://www.telerik.com/support/kb/article/b454K-hek-b454T-mb-b454c-mb.aspx
