I'm not sure what to do about this exactly. I think the Blend tool used to generate the templates correctly, it seems Visual Studio is giving basic junk as an output...

I looked at the source and both VS and Blend use the same code. I can see it is looking for ContentControl and not Window.

If you open the aero file that VS uses you can see what it should be. Or open the one that WPF uses.

Fact is, if you wanted to create your own Window derivation you should ensure the UI facilitated the behaviour of the base class. For those without more knowledge this documentation would be what you would use.

Perhaps what visual studio supplies makes sense in the UI context that you are using but it is certainly not the default Window style and control template.

I just saw your post here: #1997 (comment) which talks about checking a directory for the XAML. I could check those out. If anything, perhaps I could automate updating these articles too. I'll investigate. BTW, at the bottom of every article here, there's a link to open issues that appends a bunch of metadata. Otherwise, I have to go do that manually and edit your comment to get that data in there 😁