'{DependencyProperty.UnsetValue}' is not a valid value for property 'FocusVisualStyle'

Question

I have a weird error I\'m trying to debug with no luck.

I have subclassed hwndhost showing some content, I have the following function in that class to set to fullsc

Answer 1

This can happen when a Style is pointing to a StaticResource that does NOT exist.

This xaml was failing:

The error was:

System.InvalidOperationException: ''{DependencyProperty.UnsetValue}' is not a valid value for property 'Height'.'

When I added the missing StaticResource, the problem went away.