Article ID: 2782793 - View products that this article applies to.
Consider the following scenario:
This issue occurs because Office Communicator 2007 R2 uses a legacy Windows API to obtain a Windows logon event notification or a Windows logoff event notification.
To resolve the issue, install the following cumulative update:
(http://support.microsoft.com/kb/2755391/ )Description of the cumulative update package for Office Communicator 2007 R2: December 2012
For more information about the article, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/2709670/ )"Please wait for the System Event Notification Service" error message when users try to log on or log off a terminal server that is running Lync 2010