Mediation Server/Response Group Service/Audio Video Conferencing all failing after Windows update

[Shaunt Libarian]

Hi all

I have a brand new installation of SfB 2019 on-premise, and after the latest windows and SfB 2019 CU (September), the following services will not start:

- AV Conferencing

- App Sharing

- Response Group Service

- Mediation Service

They all appear to start, but in the Application Log (Event Viewer), i see the following errors:

- .NET framework violationm (version of framework 4.0.30319)

- Application Error (MediationServerSvc.exe version: 7.0.2046.0. Module: MEDIAP~1.DLL version 6.0.8808.20)

The exact errors are below: Mediation Server service used as an example

Error: Application Error

Invalid application name MediationServerSvc.exe, version: 7.0.2046.0, timestamp: 0x5bb4fc37
Failed module name: MEDIAP ~ 1.DLL, version: 6.0.8808.20, timestamp: 0x54f8faf6
Exception code: 0xc0000005
Error offset: 0x0000000000004282
Faulty process ID: 0x2a0c
Start time of the failed application: 0x01d5794a6e35b878
Path of the failed application: D: \ Program Files \ Skype for Business Server 2019 \ Mediation Server \ MediationServerSvc.exe
Faulty Module Path: C: \ PROGRA ~ 1 \ MICROS ~ 2.0 \ Runtime \ MEDIAP ~ 1.DLL
Report ID: ec9c26ce-635e-44d7-889a-9f0c06af60ae
Full name of the failed package:
ID of the application related to the failed package:

Error .NET Runtime:

Application: MediationServerSvc.exe
Framework Version: v4.0.30319
Description: The process was stopped because of an unhandled exception.
Exception information: System.AccessViolationException
   to <Module> .CreateEngineApiInstance (CStreamingEngineApi **, SByte *, Int32, Int32, Int32, PlatformConfig, PlatformPriority)
   at Microsoft.Rtc.Internal.Media.RtpPlatformInternal.InnerInitialize ()
   to Microsoft.Rtc.Internal.Media.RtpPlatformInternal..ctor (Microsoft.Rtc.Internal.Media.RtpPlatform, System.String, Boolean, Boolean, Boolean, PlatformConfig, PlatformPriority)
   at Microsoft.RTC.MediationServerCore.Core.Initialize ()
   at Microsoft.RTC.MediationServerCore.Server.OnStart ()
   to System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage (IntPtr, System.Object [], System.Object, System.Object [] ByRef)
   to System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage (System.Runtime.Remoting.Messaging.IMessage, System.Runtime.Remoting.Messaging.IMessageSink)
   System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem ()
   at System.Threading.ThreadPoolWorkQueue.Dispatch ()

[#2]

@Shaunt Libarian - Did you ever get a resolution to this? I'm seeing the same issues on one of my Front Ends.

Thanks!

[#3]

@AM_RSR580 , what is the faulting module path in your instance?  I ran across this once, and it was related to having UCMA Runtime 5.0 (version would be 6.0.9319.x) installed along with UCMA Runtime 6.0 (version would be 7.0.2046.x).  In that instance, there were also some Skype for Business Server 2015 items installed (Debugging Tools).  

Resolution in that instance was to uninstall Skype for Business Server 2015 components installed and UCMA Runtime 5.0.

Hope this helps.