I was searching for a way to bind a UI element to a complex type and have another complex type as FallBackValue. Unfortunately I didn't find anything on that topic. When I set FallBackValue to the name of a property or a type it is always displayed as a string :
<ContentControl Content="{Binding MyPathSelector, FallbackValue=model:PathSelector}"/>
In this case the string
model:PathSelector
will be displayed