Error message when you try to visit a Web page that is hosted on IIS 7.0: "HTTP Error 404.8 – HIDDEN_NAMESPACE"

When you try to visit a Web page that is hosted on Internet Information Services (IIS) 7.0, you may receive the following error message:

This problem occurs because the Request Filtering feature is configured for the Web server. Additionally, the Request Filtering feature contains a <hiddenSegments> element. The <hiddenSegments> element lets the administrator of the Web server deny access to a directory that is specified in the requested URL.

To resolve this problem, follow these steps:

1. Click Start, type Notepad in the Start Search box, right-click Notepad, and then click Run as administrator.
   
   Note If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
2. On the File menu, click Open, type %windir%\System32\inetsrv\config\applicationHost.config in the File name box, and then click Open.
3. In the ApplicationHost.config file, locate the <requestFiltering> element, and then locate the <hiddenSegments> element.
4. In the <hiddenSegments> element, delete the entry that matches the directory that is specified in the requested URL.
5. On the File menu, click Save.
6. Exit Notepad.