SPWebApplication.FileNotFoundPage property
SharePoint 2013
Gets or sets the name of an HTML file relative to \\Program Files\Common Files\Microsoft Shared\web server extensions\14\LAYOUTS\Locale_ID that contains the error information that is used when a file cannot be found.
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Property value
Type: System.StringA string specifying the name of an HTML file that contains error information. If the value is null or an empty string, or if the file that is referred to does not exist, SharePoint Foundation returns a standard 404 response.