Bluetooth: Bluetooth GATT Server - Part 3 of 3

Great introduction to these new API's, thanks. It's good to see this new functionality come to UWP.
IList<AppDiagnosticInfo> apps = await AppDiagnosticInfo.RequestInfoAsync();
i am getting runtime error on this line
the error is class not registered
please help me get out of this error.
I want mainwindowhandle of a process....how to do?