Symptoms
When a Unified Communications Managed API (UCMA) application creates a conference, and then joins the conference as a trusted participant, the following error entry is logged in the Front End server event logs in Microsoft Skype for Business Server 2019:
An unhandled exception was encountered in Conferencing Announcement Service
Resolution
To fix this issue, install the December 2021 cumulative update 6 for Skype for Business Server 2019, Conferencing Announcement.
