AjaxControlToolkit causes System.Security.SecurityException: Request for the permission of type ‘System.Web.AspNetHostingPermission … failed.

Here’s a quick one…

A developer was using AJAXControlToolkit in an application. Not a big deal. Except that it kept throwing that damn exception. You know the one:

Server Error in ” Application.
Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your [...]