Description Christian Damus 2019-09-13 16:44:41 EDT

In a categorization rendered as a tree, only the selected category's view is actually rendered.  For any other category in the tree, its view is not rendered and if it was rendered, then those controls (and renderers) were disposed when the selection was changed.  Consequently, navigation of a marker that should reveal a specific feature's control will not work if that control is in a category that is not selected.

Steps to reproduce:

1. Create a view model with a Categorization rendered as a tree.
2. In the editor, select a category that is not the default category selection
   and make some validation error in some control in that category's view.
3. Change the category selection to some other category.
4. Find thee marker validation problem from step 2 (in the errors view or
   diagnostic view) and double-click to navigate, assuming that your editor
   connected the go-to-marker protocol with the Reveal Service.
5. See that nothing happens and the editor remains as it was in step 4.
   This is because at step 3 the view (and controls) in which the error was made
   in step 2 were disposed.