Error message when a client user tries to use a mobile device to access a Web site that is published in ISA Server 2006: "500 Error - Element not Found"

Consider the following scenario:

• You publish a Web site in Microsoft Internet Security and Acceleration (ISA) Server 2006.
• In the Web listener, ISA Server is configured to use forms-based authentication to authenticate client requests.

However, when a client user tries to access the published Web site by using a mobile device, the user receives the following error message:

This problem occurs if the client device sends an "Accept" header that contains "text/vnd.wap.wml" in the HTTP request. In this situation, ISA Server incorrectly handles the “Accept” header.

A hotfix package is available to resolve this problem. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.