Reproduction of the crash in BS1953: https://app.bugsplat.com/v2/crash?database=Noesis&id=1953

Reproduction steps:

• Create a new ResourceDictionary document
• With the document open, open the XAML and replace it's contents with the following:

  <Page x:Class="ResourceDictionary"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  </Page>

• Go back to Studio
• Select any other document (don't close the ResourceDictionary document tab)
• Select the ResourceDictionary document (crash)