Lync Client and Server Cumulative Update Package (CU4)

The latest Lync Client and Server update (as of December 6, 2011) was released a couple of weeks ago and is called Cumulative Update (aka ‘CU4’). I finally had a chance to read about it and install it.

Note: this udpate is  referred to as the “Cumulative update for Lync Server 2010: November 2011” in the mobility documentation.

Server Updates

In addition to many fixes, as it has been reported, CU4 on the server-side is significant because that it contains updates that partially readies the server for the new Lync mobility functionality and clients that are due to be released soon (“before the end of 2011”).

This includes the addition of new Lync Powershell cmdlet’s to support the administration and configuration of the mobile experience.

If it has been awhile since you’ve installed a Cumulative Update, Tommy Clarke has a good refresher on the best practices of installing Lync updates, and specifically CU4:

One thing to keep in mind, as the KB article for the update points out, if your monitoring or archiving services are collocated with a Lync back-end, run the Install-CsDatabase cmdlet on the back-end server instead of on the the front-end. This is called out in the CU4 KB article but it is easy to miss:

“In a Lync Server 2010 Enterprise Edition environment in which the archiving/monitoring services are collocated with an Enterprise Edition back-end server, run this cmdlet from the Enterprise Edition back-end server.”

If you attempt to run it from the front-end you will receive this error:

Lync CU4 error

There were updates to most server roles and components. You can use the cumulative update installer (LyncServerUpdateInstaller.exe) to make sure all components on a particular Lync server/role are updated, but you need to run this on each Lync server – with the exception of the back-end which in some cases you can update from the front-end server with the Install-CsDatabase cmdlet (see the associated KB article for more details).

Note: as of December 12, 2011, these updates still have not appeared on Windows Update. My guess is that they will appear at the end of December (~the 27th).

Client Updates

CU4 for the Lync Client updates it from the previous 4.0.7577.314 to 4.0.7577.4051.  There were a handful of good issues fixed in this release, including an issue with anonymous meeting participants not being able to share applications. For a list of fixes this update addresses, see KB article:

There were also updates for other Lync clients:

8 comments to Lync Client and Server Cumulative Update Package (CU4)

  • Divya

    That is good to know. Thank you, Curtis!


    • Divya,

      It turns out there were some changes in late December.

      Around Dec 12th there was a very minor change to CU4 (as I originally replied to you, just a seperate installer for the UcmaWorkflowRuntime was added).

      However, much to my surprise, there were a couple of later December 2011 Lync server updates that got released under the same November 2011 CU4 knowledge base article and download link. This was done so that these updates got out right away – Microsoft did not want people to have to wait until next quarter to get these udpates via Windows Updates.

      I’ve documented this here: December 2011 Updates for Microsoft Lync Server.

      Sorry for the confusion,

  • Divya

    Did anyone notice that some of the updates in CU4 are now timestamped with a December 2011 date? I downloaded the LyncServerUpdateInstaller Package dated Dec 13th again. Compared the digital signatures of this file with the one released in November and they are different. Does anyone know what changed? Are there issues with the Nov’11 version?


    • Yes, several people have noticed that. It is the same update. The only difference is that the UcmaWorkflowRuntime.msp was made available as an independent download; previously it was included in the the cumulative update installer (LyncServerUpdateInstaller.exe).

      All the patches are the same.


  • Tommy

    Thanks Curtis. When can we expect CU4 on MU and WSUS? The Microsoft article you reference states it will be available there in late August 2011.

    • Hi Tommy,
      I do not know exactly when CU4 will appear on MU and WSUS, but I think it will be the end of this month (December).

      It usually happens in 3-4 weeks, but it can take up to two months after the updates are available on the download center. Obviously that Aug 2011 date is wrong.

      Updates from Lync product team are usually released to Microsoft Update the 4th Tuesday of every month (not the typical patch Tuesday). For this to happen, the Lync team must submit the updates to MU at the beginning of the month because the process to get them on Microsoft Update takes several weeks.

      CU4 was originally published on Nov 19th, but it was just updated on Dec 9th (a seperate UcmaWorkflowRuntime.msp was added).

      All that to say, they likely missed submission on the 4th Tuesday of November, but I don’t see why it wouldn’t be the 4th Tuesday in December – which would be the 27th.


  • […] December 2011 Updates for Microsoft Lync Server By Curtis Johnstone, on January 12th, 2012 TweetIn mid-December 2011, Microsoft released an update for Lync Server 2010. This flew under the radar for many people, including myself, because the update is distributed under the same knowledge base article (KB 2493736) and download link as the previous November 2011 CU4 update. […]

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