Basically, your own your own..
Why do I receive an "Unknown error" (C00D11CD)?
Unfortunately, this error usually occurs when another program or operating system component encounters a problem, but does not communicate the nature of the problem to the Player. Because this generic message can be displayed in a wide variety of circumstances, there is no single solution.
The Windows Media Player team at Microsoft is investigating ways to improve error detection and reporting for problems caused by underlying programs or system components. We'll provide more information about what causes these unknown errors in future columns, so keep checking back.
If you need immediate assistance, your best bet is to talk with other users who are experiencing similar problems with this error by posting your question to the Windows Media Player Newsgroup. Remember to provide information, such as what version of the Player and the Windows operating system you are using, as well as what you were trying to do just before you encountered the error. If the error occurs when you try to use a particular file, Web link, or URL, include those details as well. Many newsgroup experts, including Microsoft Most Valuable Professionals (MVPs), columnists, top newsgroup participants, and some of Microsoft's own experts, are active in this newsgroup.