Lync server 2010 rtchost.exe crashes after Windows Update.

Lync2013 After running Windows update on a Lync 2010 edge server I was unable to communicate with external contacts. I could see their presence but no chat/video or audio. The eventlog contained lots of event 1001 “Information”(Why not error !!!!!) that RTCHOST.EXE crashed. Probably failed installation of KB2982385.

Why are these only information events.rtchostexe

Even more Events of 50007 and 12331


What to do. Noticed that Windows updated had installed several security fixes and .net framwork fixes. My first thought was to uninstall all newly installed updates. Rebooted and same errors.

Next step was to run Lync server 2010 deployment wizard, selected update,add or remove features. This procedure failed With “Object of an instance not set”. This was not good……… Lync installation was most likely corrupted by a failed KB2982385 install.

Found a recently released Security update from Microsoft :

MS14-055: Description of the security update for Microsoft Lync Server 2010: September 9, 2014

Downloaded Lync hot fix for this article: Security Update for Lync Server 2010 (KB2982385, KB2982388) :  Microsoft has update this patch and removed the KB:2982385 part of it. Now it is only a update to Response Group Service.

During this install I was prompted for a driver install, this is probably why it failed during Windows updates.


Updates the edge server . Started the stopped Lync service (start-cswindowsservices) . And it worked.

I think some .net framework update had broken my server….