Unified Communications Web API (UCWA) issues that are fixed in Skype for Business Server 2015 June 2016 cumulative update 6.0.9319.259

Symptoms
This hotfix resolves the following issues:
  • When Microsoft Unified Communications Web API (UCWA) tries to create an Exchange web proxy for achieving photos or Microsoft Exchange Web Services (EWS) search purpose, there will be a storage client created within the ExchangeWebServiceProxyFactory to retrieve your initialize settings. Therefore, UCWA may have multiple WCF connections with Lync Storage Service (LYSS). This will be a potential issue for exhaust WCF connections.
  • This update adds an API to UCWA to trigger AVMCU to do video modality escalation by a REINVITE message in Skype for Business Server 2015.
  • Fixes an issue in which you can't sign in Skype for Business Server 2015 when some requests to LYSS are hold on or some work items are piled up in UCWA internal queue.
  • When you send instant messaging (IM) messages, UCWA crashes with a null reference error.
  • When user's endpoint is in ended state but the UCWA application is still in established state, the incoming INVITE message will be delivered between user endpoint and static default endpoint infinitely.
  • Fixes an issue that occurs during the call escalation process by using UCWA in a Microsoft Skype for Business Server 2015 environment.

    In this situation, the following event is logged:

    Log Name: Lync Server
    Source: LS UCWA
    Date:DATE/TIME
    EventCategory:1099
    EventLevel:1
    UserName: N/A
    EventDisplayNumber: 2000320003
    EventDescription
    UCWA encountered an unhandled exception.

    Exception: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
    at Microsoft.Rtc.Collaboration.LocalEndpoint.CallKeyUpdated(String previousCallKey, String newCallKey)
    at Microsoft.Rtc.Collaboration.Call.UpdateRemoteParticipantAndCallId(IncomingInviteData inviteData, SignalingSession session, Boolean isPrimary)
    at Microsoft.Rtc.Collaboration.Call.ProcessAndCreateFinishEscalationAsyncResult(Boolean isSuccessful, AsyncCallback userCallback, Object state)
    at Microsoft.Rtc.Collaboration.Call.BeginFinishEscalation(Boolean isSuccessful, AsyncCallback userCallback, Object state)
    at Microsoft.Rtc.Collaboration.Conferencing.EscalateToConferenceAsyncResult.b__1a(CallSession callSession)
    at System.Collections.Generic.List`1.ForEach(Action`1 action)
    at Microsoft.Rtc.Collaboration.Conferencing.EscalateToConferenceAsyncResult.CommitEscalation(EscalationEndpointContainer endpoint)
    at Microsoft.Rtc.Collaboration.Conferencing.EscalateToConferenceAsyncResult.CommitEscalation()
    at Microsoft.Rtc.Collaboration.Conferencing.EscalateToConferenceAsyncResult.CompleteCore(RealTimeException completionException)
    at Microsoft.Rtc.Signaling.SipAsyncResult`1.MakeCallback(Object state)
    at Microsoft.Rtc.Signaling.SipAsyncResult`1.Complete(TEx ex, Boolean synchronousCompletion)
    at Microsoft.Rtc.Collaboration.Conferencing.EscalationAsyncResult.FinishCompleting()
    at Microsoft.Rtc.Collaboration.Conferencing.EscalateToConferenceAsyncResult.ProcessDialOutQueueOrCompleteEscalationIfNeeded(Object state)
    at Microsoft.Rtc.Signaling.QueueWorkItemState.ExecuteWrappedMethod(WaitCallback method, Object state)
    at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
    at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
    at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
    at System.Threading.ThreadPoolWorkQueue.Dispatch()
    Cause: An unhandled exception happened.
    Resolution:
    Restart the server. If the problem persists contact product support.

  • Fixes an issue that occurs when there're instant messaging (IM) calls incoming through Microsoft Unified Communications Web API (UCWA) in Microsoft Skype for Business Server 2015. In this situation, the following event is logged:

    Log Name: Lync Server
    Source: LS UCWA
    Date:DATE/TIME
    EventCategory: 1099
    EventLevel: 1
    UserName: N/A
    EventDisplayNumber: 20003

    Event Description

    UCWA encountered an unhandled exception.
    Exception: System.ArgumentNullException: Value cannot be null.
    Parameter name: collection
    at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
    at Microsoft.Rtc.Collaboration.InstantMessagingMediaCapabilities..ctor(List`1 supportedContentTypes)
    at Microsoft.Rtc.Collaboration.InstantMessagingCall.ProcessIncomingInviteOffers(SdpOffer offer)
    at Microsoft.Rtc.Collaboration.Call.InitializeIncomingSession(SignalingSession signalingSession, IncomingInviteSessionRequestData incomingInviteRequestData)
    at Microsoft.Rtc.Collaboration.LocalEndpoint.ProcessIncomingCall(IncomingInviteSessionRequestData incomingInviteRequestData, SessionReceivedAsyncEventArgs e, RealTimeException& caughtException, Int32& rejectionResponseCode, Nullable`1& diagCode, IncomingInviteSessionDataHolder incomingDataHolder, Call callToReplace, Call& call, List`1 callSelectionMediaTypes, Conversation conversation)
    at Microsoft.Rtc.Collaboration.LocalEndpoint.ProcessIncomingSignalingSession(IncomingInviteSessionRequestData incomingInviteRequestData, SessionReceivedAsyncEventArgs e)
    at Microsoft.Rtc.Collaboration.LocalEndpoint.InitializeInvitationScreeningDataCompleted(IAsyncResult result)
    at Microsoft.Rtc.Signaling.SipAsyncResult`1.MakeCallback(Object state)
    at Microsoft.Rtc.Signaling.QueueWorkItemState.ExecuteWrappedMethod(WaitCallback method, Object state)
    at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
    at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
    at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
    at System.Threading.ThreadPoolWorkQueue.Dispatch()
          
    Cause: An unhandled exception happened.
    Resolution:
    Restart the server. If the problem persists contact product support.

Resolution
To fix this issue, install the June 2016 cumulative update 6.0.9319.259 for Skype for Business Server 2015 and Unified Communications Managed API 5.0 Runtime.
Properties

Article ID: 3170156 - Last Review: 06/30/2016 08:08:00 - Revision: 3.0

Skype for Business Server 2015

  • kbfix kbqfe kbsurveynew kbexpertiseadvanced KB3170156
Feedback