Consider the following scenario in a Microsoft Skype for Business Server 2019 environment:
- You have installed the July 2019 cumulative update 7.0.2046.123 for Skype for Business Server 2019, Conferencing Server.
- You have a third-party contact center or other application that's based on Microsoft Unified Communications Managed API (UCMA). UCMA is used to manage conferences and adjust Audio/Video Conferencing Server audio routes.
In this scenario, you randomly experience conferencing audio/video failures. Additionally, you may notice that the following event log entry is recorded on one or more of your Skype for Business 2019 Front End servers:
Source: LS Audio-Video Conferencing Server
Message: The Audio/Video Conferencing Server has failed to create a conference.
Conference URI: URI;gruu;opaque=app:conf:focus:id:abcdefgh Exception: Media Processor instance is not available to service this request
This issue occurs because the Audio/Video Conferencing Server experiences a deadlock under certain timing conditions.
Microsoft is researching this problem and will post more information in this article when it becomes available.