Error when adding new extensions to the library

An error occurs when you add a new file or image extension to the Library Management properties:  The file type has not been added. Please see administrator.

Before you can add a new file or image extension to the library properties, you must first add that extension to the library file types whitelist.

Adding an Extension to the Library Files Whitelist

Prerequisite: You have permission to edit files on the Ektron server.

1. Open siteroot\web.config .
2. Find the element that begins with ek_LibFileTypeWhiteList.
3. Add the new extension to that list of file extensions.
   NOTE: Extensions begin with an asterisk (*), then a period (.), followed by the extension, and a comma.  For example:  *.txt,
4. Save web.config .

After completing the procedure, you can add the new file extension to the library properties.