Article ID: 943020 - View products that this article applies to.
When you try to send a Subscribe request in Microsoft Office Communications Server 2007, you receive the following error message:
SIP/2.0 481 Subscription Does Not Exist
To resolve this problem, apply the Communications Server 2007 update package for the Unified Communications Managed API v1.0 Redistribution that is dated December 17, 2007. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/944285/ )Description of the Communications Server 2007 update package for the Unified Communications Managed API v1.0 Redistribution: December 17, 2007
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.