When observing the Server Group in the StoreFront management console, for each Server Member server the notification "Server is not reachable. Configuration settings might be out of date." is displayed with a red exclamation point icon. When initiating propagation the StoreFront management console crashes referencing the Citrix.DeliveryServices.Admin.SnapIn.dll.
The domain account initially used to trigger propagation was NOT a member of the the local StoreFrontAdmins group on each Server Group StoreFront server member.