Be carefully with updating your LCS/OCS Servers with the following patch

http://support.microsoft.com/kb/974571 --> MS09-056: Vulnerabilities in CryptoAPI could allow spoofing

you might get these events saying that this eval version of LCS has expired or that the protocol stack cannot be initialized etc..

For more Information read these blog postings:

• http://communicationsserverteam.com/archive/2009/10/14/632.aspx
• http://blogs.technet.com/dodeitte/archive/2009/10/13/do-not-apply-kb974571-to-lcs-ocs-servers.aspx
• http://www.formortals.com/kb974571-ocs-or-lcs-bad-news-do-not-install/

Do not deploy this patch and wait until Microsoft comes up with a solution..

Update

Ruben and I submitted this post at the exact same time, what are the odds ;-)

Anyway he noticed this problem this morning on his OCS 2007 R2 Front-End server...

He got this event in his eventlogs

Event Type:        Error
Event Source:    OCS Server
Event Category:                (1000)
Event ID:              12290
Date:                     14/10/2009
Time:                     13:43:41 PM
User:                     N/A
Computer:         
Description:
The evaluation period for Microsoft Office Communications Server 2007 R2 has expired. Please upgrade from the evaluation version to the full released version of the product.

Sincerely,

Tonino Bruno | ICT Consultant | PRO-Exchange Community