You might see the following 2 Event ID’s on your server if your have certificates in the wrong store:

  • Event ID 32042 LS User Services
    Invalid incoming HTTPS certificate
    cause: This can happen if the HTTPS certificate has expired or is untrusted



Open up Lync Management Shell and run the following command:

    Get-Childitem cert:\LocalMachine\root -Recurse | 
    Where-Object {$_.Issuer -ne $_.Subject} | 
    Format-List * | Out-File c:\computer_filtered.txt

If the text file lists certificates then you know which ones to remove/move. After you have cleaned up, reboot your server and all should be fine.

One thing to also take note of, your Lync client will show other users status as “Updating”. Once the server is rebooted it changes to there current status.

#region - PowerShell 4.0
(Get-ChildItem Cert:\LocalMachine\Root -Recurse).Where({$_.Issuer -ne $_.Subject})

Force Update LYNC Client Address Book using PowerShell