You may experience unexpected behavior when you send a request for a resource that has the .map file name extension to a server that is running IIS

You may experience unexpected behavior when you send a request for a resource that has the .map file name extension to a server that is running Internet Information Services (IIS). This issue may occur because of the algorithm that IIS uses to determine whether the resource contains a valid server-side image map. In the following versions of IIS, the .map file name extension is reserved for server-side image map processing:

• IIS 6.0
• IIS 5.1
• IIS 5.0

Do not use the .map file name extension for other purposes.

When you send a request for a resource that has a .map file name extension to IIS, you may experience one or more of the following symptoms:

• The XML source or the code source of the resource appears in the browser window.
• A list of the files appears in the browser window. These files are in the folder in which the .map file is located.

Note You may experience symptoms that are not listed.

For more information about issues that may occur in IIS 5.0 if a file is larger than 128 KB and if it has the .map file name extension, click the following article number to view the article in the Microsoft Knowledge Base: