Category Archives: Lync

Exchange UM Voice Auto-Attendant custom greeting and those pesky system prompts

Microsoft Exchange Unified Messaging is a very cool tool to put into your corporate telephony arsenal.  You get a very nice, voice activated auto-attendant with some very nice features.
One feature the Exchange UM team didn’t get fully right is customization of the initial greeting.

Out of the box, your voice enabled AA (auto-attendant) will say:

Thank you for calling [your company name] To reach a specific person, just tell me their name

If you are like ArmgaSys, you will want to customize your greeting via the ECP (Exchange Admin Center).  You hire voice talent and record a really nice greeting along the lines of “Thank you for calling my company, if you know your parties extension, you may dial it now or simply tell me their name”.  You then upload your greeting in the UM and are shocked to hear the following:

Thank you for calling my company, if you know your parties extension, you may dial it now or simply tell me their name. To reach a specific person, just tell me their name.

You just discovered a UM system prompt, specifically the Voice AA prompt which says (in a female voice) “To reach a specific person, just tell me their name”

At this point, you have only one option:  You must replace the system prompt with a audio file containing silence.*  Fortunately, this is very easy to do!

The solution:

  1. On your Exchange UM server, navigate to
    C:\Program Files\Microsoft\Exchange Server\V[#]\UnifiedMessaging\prompts\en\
  2. Delete the file vuiAADsearch_Yes_Custom_No_main.1.wav
  3. Make a copy of Silence-250ms.wav
    (This .wav file is also located in the prompts\en directory)
  4. Rename your copy of the silence file to vuiAADsearch_Yes_Custom_No_main.1.wav

That is it!

Warning! Warning! Warning!
Installing cumulative updates (CU) and service packs will revert this file back to its original state.  You will need to repeat these steps after each CU and Service Pack!


*Some of you will be asking “Why not just delete the file”.  Well, it is a system prompt which means Exchange UM pretty much requires the file to be there.  Deleting the file can (and will) cause your UM service to fail.

No connectivity with the Lync Web App reported every 20 minutes or so

We seem to see to encounter a specific connectivity error a lot across a variety of Lync environments.  In some instances, users will complain about slow connectivity or no connectivity.  The primary symptom is the following event log entry (repeated every 20 minutes or so):

No connectivity with the Lync Web App. Affected Web browser clients cannot use Web Conferencing modality.

Server Machine FQDN:, Port:8061
Server Type: External-WebApp-Edge [HTTP side error:The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.]
If the problem persists this event will be logged again after 20 minutes
Cause: Service may be unavailable or Network connectivity may have been compromised.

Never fear, this one is easy to fix!

The Root Issue
The application pool registered to the Lync Server External Web Site\Reach application is set to activate On Demand.  This results in an IIS application pool that is not spun up when an external reach request is received resulting in a connectivity fault.


The Solution
Important:  The UI based solution only works in IIS8.  If you are running IIS7.5,  See the “Manually Fix This Issue” below 

  1. Launch Internet Information Services (IIS) Manager on your front-end pool server
  2. Navigate to Sites –> Lync Server External Web Site –> Reach
  3. Right click on Reach and select Manage Application –> Advanced Settings
  4. Note the Application Pool in the advanced settings pop-up
    This will be set to LyncExtReach in normal environments
  5. Click on Application Pools and locate the application pool noted in step#4 above
  6. Right click on the Application Pool and select Advanced Settings
  7. Change the Start Mode to AlwaysRunning
  8. Restart IIS


Told you it was easy!


UPDATED 09/2014:  How to Manually Fix This Issue
Running IIS7.5?  Don’t see the Start Mode in IIS, here is the manual method!

  1. Edit the following file in the editor of your choice
    Important:  Make sure you are running your editor as an Administrator!
  2. Search for name=”LyncExtFeature”
    Important:  You are looking for the <add name=”LyncExtReach” within the <system.applicationHost><applicationPools> section!
  3. Edit the entry to include the startMode attribute (see bold text below)
    <add name=”LyncExtReach” autoStart=”true” managedRuntimeVersion=”v4.0″ managedPipelineMode=”Integrated” startMode=”AlwaysRunning”>
  4. Save the file and restart IIS

Exchange Unified Messaging Doesn’t Start (No Certificate Found)

So, you have updated your SSL certificates in Exchange 2010 to comply with (insert corporate policy here).  All seems well until you receive a frantic call: “Voice Mail is down!”.

A quick search of the event viewer turns up:

The Microsoft Exchange Unified Messaging service was unable to start. More information: “Microsoft.Exchange.UM.UMService.UMServiceException: No certificate was found using the thumbprint ” specified in the UMCertificateThumbprint property of the UMServer object.
   at Microsoft.Exchange. UM.UMService.UMConnectionManagerHelper.TLSConnectionManager.Initialize()
   at Microsoft.Exchange.UM.UMService.UMService.InitializeConnectionManager()
   at Microsoft.Exchange.UM.UMService.UMService.StartService()
   at Microsoft.Exchange.UM.UMService.UMService.OnStartInternal(String[] args)”


You cradle your head in your hands and begin to weep softly.

Fear not!

The Solution

  1. Launch Exchange Management Console from the server hosting the Unified Messaging Role
    Important: Remember to launch with UAC elevated permissions!
  2. Expand and click on Server Configuration
  3. From the server list in the center pane, select the server hosting the Unified Messaging Role
  4. In the lower center pane, you’ll very likely notice the new SSL certificate is not assigned to any services
  5. Right click on the certificate and select Assign Services to Certificate
  6. In the wizard, check the Unified Messaging (UM) service
  7. Finish the wizard and dry your tears!