Cannot remove the Director Pool – Users or Contacts are associated to it.

While trying to decommissioning a Lync Server 2013 Director Pool we got the following error message when we publish the new topology:

This wasn’t expected since a Director Pool shouldn’t have users associated with it.

After troubleshooting the issue, we notice that some users had the attribute msRTCSIP-PrimaryHomeServer associated to the Lync Server 2013 Director Pool.
These users were previously moved to Skype for Business Online, during the move the attribute was updated to the Director Pool that was configured as federation route.
Please note that this behaviour can also happen if we have a Front End Server Pool in the federation route.

Because the msRTCSIP-PrimaryHomeServer attribute isn’t used by Skype for Business Online we can clear it.

The first step is to get the Pool Distinguished Name and the quickest way is using View Logs in the Publishing Wizard:

Then, we Expand all Actions and scroll down to Check Orphaned Users:

In this example the Pool Distinguished Name is:

CN=Lc Services,CN=Microsoft,CN=1:8,CN=Pools,CN=RTC Service,CN=Services,CN=Configuration,DC=uclobby,DC=com

And we assign it to a variable ($PoolDN):

$PoolDN=”CN=Lc Services,CN=Microsoft,CN=1:8,CN=Pools,CN=RTC Service,CN=Services,CN=Configuration,DC=uclobby,DC=com”

Alternatively, we can use PowerShell to get the Pool Distinguished Name:

Import-module ActiveDirectory
$RTCDN = “AD:\CN=*,CN=Pools,CN=RTC Service,CN=Services,CN=Configuration,”+(Get-ADDomain).distinguishedname
$PoolDN=”CN=Lc Services,CN=Microsoft,”+(Get-ItemProperty -Path $RTCDN -Name dNSHostName,distinguishedname | ?{$_.dNSHostName -eq “<POOL FQDN>“}).distinguishedname

Now we can list the all users that have msRTCSIP-PrimaryHomeServer attribute associated to the pool:

Get-CsUser -LDAPFilter “(msRTCSIP-PrimaryHomeServer=$PoolDN)” | Select SamAccountName,DisplayName,SipAddress,HostingProvider | ft -AutoSize

Note: We can only use this workaround if the HostingProvider is

If we have few users we can simply clear the msRTCSIP-PrimaryHomeServer attribute manually:

Get-ADuser <USERACCOUNT> | Set-ADObject -Identity $_.distinguishedname -Clear “msRTCSIP-PrimaryHomeServer”

However, if we want to clear the attribute for all users associated to the Lync Server 2013 Director Pool we should use the following:

Get-ADObject -LDAPFilter “(& (msRTCSIP-PrimaryHomeServer=$PoolDN)(” | Set-ADObject -Clear “msRTCSIP-PrimaryHomeServer”

Note: We added the msRTCSIP-DeploymentLocator since we can only clear the msRTCSIP-PrimaryHomeServer if the users were moved to Skype for Business Online.

After clearing the msRTCSIP-PrimaryHomeServer attribute we successfully remove the Lync Server 2013 Director Pool:

Lync/SfB: Quickly access the Certificate Store

In a previous post we wrote about the Checks to do in the Lync/Skype for Business Server Certificate Store, however, sometimes we might also want to manually check it using the Certificate Store MMC.

Since Windows Server 2012 and Windows 8 we can quick access the Certificate Store MMC, for Local Computer and Current User, using Command Prompt/PowerShell or the Windows Search:

Local Computer


Note: Using the Windows Search we need to add the .msc – certlm.msc

Current User


Note: Using the Windows Search we need to add the .msc – certmgr.msc 

Please also check the original post:

PKI Tip: Certificate Store Shortcuts

Lync/SfB Server: Stop Front End service in Starting state

Some of the cases we work have the Front End service in a Starting state:

In PowerShell the status is StartPending:

We cannot stop it on the Services Management Console:

We can go to Task Manager and try to manual stop the service:

If that doesn’t work we need to Go to Details and End task that is associated with the service:

Another simple way to stop all Starting services is by using the following PowerShell cmdlet. We will get a prompt for each service:

Get-Service | ?{$_.Status -eq “StartPending”} | Stop-process



Lync/SfB Server: Event 41026, LS Data MCU after May 2017 .NET Framework update

Update 2017/06/28 – In Workaround #1 we also need to request new Front End certificates with Client and Server authentication in the EKU.

Recently we notice that Lync Server 2010/2013 and Skype for Business Server 2015 Front Ends were generating the Events 41025 and immediately after the Event 41026:

Log Name: Lync Server
Source: LS Data MCU
Date: 5/23/2017 5:31:45 PM
Event ID: 41025
Task Category: (1018)
Level: Information
Keywords: Classic
User: N/A
Connection to the Web Conferencing Edge Server has succeeded

Edge Server Machine FQDN:, Port:8057

Log Name: Lync Server
Source: LS Data MCU
Date: 5/23/2017 5:31:45 PM
Event ID: 41026
Task Category: (1018)
Level: Error
Keywords: Classic
User: N/A
No connectivity with any of Web Conferencing Edge Servers. External Skype for Business clients cannot use Web Conferencing modality.

Cause: Service may be unavailable or Network connectivity may have been compromised.
Verify all Web Conferencing Edge Services in the topology are running, and network connectivity is available.

External Users also reported that couldn’t use WhiteBoard, Polls, Q&A or present PowerPoint with the following errors messages:

We can’t connect to the server for sharing right now.

Network issues are keeping you from sharing notes and presenting whiteboards, polls and uploaded PowerPoint files.

While this is still being investigated a KB article was release with the current workarounds:

LS Data MCU events 41025 and 41026 are constantly generated after you install the May 2017 .NET Framework

The issue is OS independent and affects Lync Server 2010, Lync Server 2013 and Skype for Business Server 2015 and here is a list of the .Net Framework KBs:

  • Windows Server 2008 R2

Description of the Security and Quality Rollup for the .NET Framework 3.5.1 for Windows 7 and Windows Server 2008 R2: May 9, 2017 (KB4014504)
Note: Lync Server 2010 only

Description of the Security Only update for the .NET Framework 3.5.1 for Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1: May 9, 2017 (KB4014579)
Note: Lync Server 2010 only

Description of the Security and Quality Rollup for the .NET Framework 4.5.2 for Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1, and Windows Server 2008 Service Pack 2: May 9, 2017 (KB4014514)

Description of the Security Only update for the .NET Framework 4.5.2 for Windows 7 SP1, Windows Server 2008 R2 SP1, and Windows Server 2008 SP2: May 9, 2017 (KB4014599)

  • Windows Server 2012

Description of the Security and Quality Rollup for the .NET Framework 4.5.2 for Windows Server 2012: May 9, 2017 (KB4014513)

Description of the Security Only update for the .NET Framework 4.5.2 for Windows Server 2012: May 9, 2017 (KB4014597)

  • Windows Server 2012 R2

Description of the Security and Quality Rollup for the .NET Framework 4.5.2 for Windows 8.1 and Windows Server 2012 R2: May 9, 2017 (KB4014512)

Description of the Security Only update for the .NET Framework 4.5.2 for Windows 8.1 and Windows Server 2012 R2: May 9, 2017 (KB4014595)

  • Windows Server 2016

Windows 10 Version 1607 and Windows Server 2016: May 9, 2017—KB4019472 (OS Build 14393.1198)

This .NET Framework update adds an additional check to the certificate on Enhanced Key Usage (EKU), since all Lync/SfB Server by default use Web Server template, they will only have the Server Authentication in the EKU.

As mentioned in the KB4023993 we can use two workarounds:

Workaround #1

Request new Edge Internal and Front End Pool Certificate with Client and Server Authentication

This workaround requires that we request a new certificate on the Edge Server Internal Interface and in all Front End Servers.

Open the Certification Authority snap-in, right click on Certificate Templates, and then select Manage:

Now in the Certificate Templates Console window, locate the Web Server template, right-click it, and then select Duplicate Template:

In the New Template window select General and add a name:

Note: Please take note of Template Name – WebServerClientandServer. We need to use it to request the new certificate.

In the Extensions Tab , select Application Policies and Edit it:

Add the Client Authentication:

Both Authentication should be present:

Back in Certification Authority snap-in, right click on Certificate Templates > New > Certificate Template to Issue:

Select the new template:

Now that we have the template with Client and Server Authentication, we need to request a new Edge Server Internal Certificate with the recently created template.

Request-CsCertificate -New -Type Internal -Template WebServerClientandServer -FriendlyName “Edge Internal with Client and Server Auth” -Output C:\UCLobby\EdgeIntCliSrv.req

Note: We can also use the -PrivateKeyExportable $true switch to allow the private key to be exported.

In the Active Directory Certificate Services select Request a certificate:

Example: http://ca.gears.lab/certsrv/

Advanced certificate request:

Submit a certificate request by using a base-64-encoded CMC or PKCS #10 file, or submit a renewal request by using a base-64-encoded PKCS #7 file.

We need to select the new certificate template and submit:

We download the new certificate and copy it to the Edge Server and import it:

On the Edge Server import and assign the new certificate:

Import-CsCertificate -Path C:\UCLobby\EdgeIntCliSrv.cer

Note: If we specify the -PrivateKeyExportable $true in the Request-CsCertificate we also need to add it to the Import-csCertificate.

Set-CsCertificate -Type Internal -Thumbprint 335d17df1520a5e30beee96406ffa53e20805342

Please also request new certificates for the Front End Servers with Client and Server Authentication.

After restarting the Lync/SfB Edge and Front End Services the issues should be fixed and external users should be able to use WhiteBoard, Polls, Q&A or present PowerPoint without issues.

Workaround #2

Add a registry key to temporary disable the EKU check

On the all Lync/SfB Front Ends disable the check for the Web Conferencing Service.

Please note that these registry keys are for the default install locations. We can use the following script to assist adding the registry key in the correct location:

Lync/SfB Server: Disable EKU check for Web Conferencing Service

Lync Server 2010

reg add HKLM\SOFTWARE\Microsoft\.NETFramework\v2.0.50727\System.Net.ServicePointManager.RequireCertificateEKUs /v “C:\Program Files\Microsoft Lync Server 2010\Web Conferencing\DataMCUSvc.exe” /t REG_DWORD /d 0 /f

Note: Lync Server 2010 still uses the .NET 3.5 this is why we use v2.0.50727.

Lync Server 2013

reg add HKLM\SOFTWARE\Microsoft\.NETFramework\v4.0.30319\System.Net.ServicePointManager.RequireCertificateEKUs /v “C:\Program Files\Microsoft Lync Server 2013\Web Conferencing\DataMCUSvc.exe” /t REG_DWORD /d 0 /f

Skype for Business Server 2015

reg add HKLM\SOFTWARE\Microsoft\.NETFramework\v4.0.30319\System.Net.ServicePointManager.RequireCertificateEKUs /v “C:\Program Files\Skype for Business Server 2015\Web Conferencing\DataMCUSvc.exe” /t REG_DWORD /d 0 /f

After adding the registry key simply restart the Web Conferencing Service


Stop-CsWindowsService -InputObject RTCDATAMCU
Start-CsWindowsService -InputObject RTCDATAMCU


Now the external users will be able to use WhiteBoard, Polls, Q&A or present PowerPoint without issues.

Lync/SfB Server: Manually update the Edge Server Configuration

In a recent support case we had a case that the customer had some urgency to add a new Allowed Domain to be quickly pushed to his Skype for Business 2015 Edge Servers.

However, the replication wasn’t working:

Get-CsManagementStoreReplicationStatus | ft -AutoSize

An easy solution to this is to perform a manual update and then fix the replication.

First, we need a copy of the latest configuration:

Export-CsConfiguration -FileName C:\UCLobby\

Now copy the file to each Edge Server and execute the following PowerShell cmdlet:

Import-CsConfiguration -FileName C:\UCLobby\ -LocalStore

Note: In this case we need to specify the LocalStore switch so it updates the local database.

This is also possible if we run, on each Edge ServerStep 1 from the Skype for Business Server Deployment Wizard:

Please note that manually updated the Edge Server configuration probably won’t fix the replication issue:

These steps are valid to Lync Server 2010/2013 and Skype for Business Server 2015.

This should be only use as a quick workaround to update the local store while we fix the replication issue.

PSScript: Lync/SfB Server Certification Store Validation

In a previous post, we published the checks/validations that we should do in the Certification Store in the Lync/SfB servers.

Checks to do in the Lync/SfB Certificate Store

We decided to write a PowerShell with all these checks to make it simple to use. The script will be kept in sync with the post, meaning that when a new check is added, it will also be included in the script.

The PowerShell script is available in the TechNet Gallery:

Lync/Skype4B Certification Store Validation

Both script usage and change log are included in the TechNet Gallery description.

Address Book search for “First + Last Name” when Display Name is “Last, First Name” (WebSearchOnly)

It is quite common to have users stored in Active Directory (AD) with “Last, First Name” (e. g., “Paulino, David”). Since Lync/SfB is heavily dependent on AD, what will happen to users that want to search for “First + Last Name”?

Regarding the Address Book download, this is an issue that has already been discussed in a previous post:

Last + First name searches in Lync/Skype4B Address Book (GalContacts.db)

However, when we use WebSearchOnly and we have the AD Display Name as “Last, First Name”, we may get some complaints from users saying they cannot search for “First + Last Name”. The reason for this is most likely that their intention is to search for a user with additional text in their Display Name, like “Carmine, Anthony (COG)”, but they end up searching only for “Anthony Carmine”.

Here are some examples:


Looking in the RTCAB database, we notice that Display Names with a comma have more entries:





Note: The attribute 3 represents the Display Name:



Again, this will only work if we have a comma in the Display Name. Without it, we will only be able to search for the Display Name itself: