Lync Server 2010 Hotfix KB 2493736
Updates that are released for Lync Server 2010
Update for Administrative Tools
2467771 (https://support.microsoft.com/kb/2467771/ ) Description of the update package for Lync Server 2010, Administrative Tools: January 2011
Update for Core Components
2500444 (https://support.microsoft.com/kb/2500444/ ) Description of the cumulative update for Lync Server 2010, Core Components: April 2011
Update for Conferencing Server
2514975 (https://support.microsoft.com/kb/2514975/ ) Description of the cumulative update for Lync Server 2010, Conferencing Server: April 2011
Update for Web Components Server
2500441 (https://support.microsoft.com/kb/2500441/ ) Description of the update package for Lync Server 2010, Web Components Server: April 2011
Update for Standard/Enterprise edition Server
2500442 (https://support.microsoft.com/kb/2500442/ ) Description of the update for Lync Server 2010: April 2011
Update for Web Conferencing Server
2530592 (https://support.microsoft.com/kb/2530592/ ) Description of the cumulative update for Lync Server 2010, Web Conferencing Server: April 2011
Update for Mediation Server
2502810 (https://support.microsoft.com/kb/2502810/ ) Description of the cumulative update for Lync Server 2010, Mediation Server: April 2011
Update for Unified Communications Managed API 3.0 Runtime
2500448 (https://support.microsoft.com/kb/2500448/ ) Description of the cumulative update for Lync Server 2010, Unified Communications Managed API 3.0 Runtime: April 2011
More detail here
Download here
Comments
Anonymous
April 21, 2011
After installing this update our users could join Online Meetings through the Internal Web Site, but not through the External Web Site (the Lync page appears but nothing happens in Lync). After uninstalling this update everything worked fine again..Anonymous
April 28, 2011
I Think this fix will help you blogs.technet.com/.../lync-2010-hotfix-kb-2540951-64-bit.aspx