The LcsLog purge job may fail with the following error message in Microsoft Skype for Business Server 2019 or Skype for Business Server 2015:
Message: The DELETE statement conflicted with the REFERENCE constraint "FK_FocusJoinsAndLeaves_4". The conflict occurred in database "LcsLog", table "dbo.FocusJoinsAndLeaves". The statement has been terminated.
To fix this issue, install one of the following updates: