Error message when you visit a Web site that is hosted on IIS 7.0: "HTTP Error 404.5 – URL Sequence Denied"


You have a Web site that is hosted on Internet Information Services (IIS) 7.0. When you visit the Web site in a Web browser, you may receive an error message that resembles the following:
Server Error in Application "application name"
HTTP Error 404.5 – URL Sequence Denied
Description of HRESULT # The operation completed successfully.


This problem occurs because the requested URL matches the sequence in the <denyUrlSequences> node in the ApplicationHost.config file.


Important These steps may increase your security risk. These steps may also make the computer or the network more vulnerable to attack by malicious users or by malicious software such as viruses. We recommend the process that this article describes to enable programs to operate as they are designed to or to implement specific program capabilities. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this process in your particular environment. If you decide to implement this process, take any appropriate additional steps to help protect the system. We recommend that you use this process only if you really require this process.

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 <denyUrlSequences> node.
  4. Delete the sequence that matches the requested URL.

    For example, delete the code that resembles the following.
    <add sequence=”<sequence>” />
    Note <Sequence> is a placeholder for the sequence that matches the requested URL.
  5. Save the ApplicationHost.config file.


To work around this problem, do not use a URL that matches the sequence in the <denyUrlSequences> node.