Microsoft Office Communicator client consistently crashing when making or receiving audio calls

Problem

Ran into an interesting problem at an engineering company after deploying IM and Presence 2 months ago for them. Enterprise voice has not been deployed yet (this project just kicked off yesterday), so users have been using communicator calls to other coworkers. A small number of the 30 or so users who were in the pilot began reporting that their MOC client would crash when making or receiving audio calls. The recommendations we found through the research done on the internet and the information we got back from Microsoft was that we needed to update the MOC client with the latest patch but all of the users were already using the latest patch available from May 2010. The IT analyst here has 1 desktop and 1 laptop and while his desktop constantly crashes, his laptop doesn’t.

What’s strange is that there was a user who had no problems in the Toronto office but started experiencing issues after she moved to the Ottawa office which was on a different subnet. The voice calls from Toronto would crash but not locally in Ottawa office so a test was done from a desktop on same subnet with another laptop, the first call worked but when tried from different computer, it would crash.

After reaching out to a support engineer from the Microsoft Partner Support Forum, a recommendation to use Process Explorer from SysInternals to try and figure out what service might be causing MOC to crash. After doing a bit of poking around, we originally thought it was the iTune service but later discovered that it wasn’t.

Resolution

Long story short, the problem ended up being an application called NetSupport that was used for managing desktops. This application had a hook into the audio and video which would explain why MOC would crash upon receiving calls.

The version that caused the MOC client to crash was NetSupport for Windows 32 bit Client 10.60.6. Once we updated it to version 11.00.2, the problem went away:

I’m sure this will help me in the future when I’m troubleshooting this type of issue as I’ll always be on a lookout for any applications running in the background that may have a hook on the audio and video of a desktop/laptop.