Very brief note, so I don’t forget the circumstances: I may write a sample later. When you define Prism region in your view like this:<\/p>\n
Prism has two-staged process that brings your region to existance. First it needs to create a The trouble is, if there is a <igDock:TabGroupPane prism:RegionManager.RegionName=\"SomeRegion\" \/> <\/code><\/p>\nRegion<\/code> object, this is done by DelayedRegionCreationBehavior<\/code>. Then it attaches your region to a region manager in RegionManagerRegistrationBehavior<\/code>. The $1M question is: what region manager? To answer that, Prism walks up the logical tree to find a parent view with an already attached region manager (e.g. the shell).<\/p>\nContentPresenter<\/code> in the way, it won’t work. Experiment shows that ContentPresenter<\/code> adds its child to the visual tree, but not to the logical tree. See also here<\/a>. So, the region manager instance won’t be found, and the region object will be created, but not added to any region manager.