After you install February 2017 update for Skype for Business Server 2015 (build 6.0.9319.277), synthetic transactions don't work as expected. For example, when you run the Test-CsUcwaConference (UcwaConference) cmdlet, you receive the following error message:
Error Message: Failed creating application activity.
Inner Exception: Method not found:
'System.Threading.Tasks.Task`1<Microsoft.Rtc.Internal.Ucwa.ClientModel.Interfaces.IHttpResult>
Microsoft.Rtc.Internal.Ucwa.ClientModel.Interfaces.IMeService.MakeMeAvailableAsync(Microsoft.Rtc.Internal.Ucwa.ClientModel.ApplicationSignInProperties)'.