Assembly: System.Web (in System.Web.dll)
Potentially dangerous data was received from the client.
The HttpRequest class uses input validation flags to track whether to perform validation on the request collections accessed through the Cookies, Form, and QueryString properties. The method sets these flags so that when the get accessors for the Cookies, Form, or QueryString property are invoked, input validation is performed. Validation works by checking all input data against a hard-coded list of potentially dangerous data.
If the validation feature is enabled by page directive or configuration, this method is called during the page's ProcessRequest processing phase. The method can be called by your code if the validation feature is not enabled.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.