If you are using the latest version of Blend (for Visual Studio 2013) and XAML, you may have noticed something weird: Suddenly, in some places of your XAML markup, an unwanted FontFamily property appears: FontFamily=”Global User Interface”
This is unfortunately caused by a bug in Blend. In my experience, it is not quite clear what exactly is causing the issue, but the fact is that suddenly for no reason, your FontFamily gets overwritten.
In most cases, it is fairly easy to solve: Just delete the faulty FontFamily attribute and all is well. I never noticed that it was actually overwriting an existing FontFamily attribute, instead it just adds the Global User Interface font family to elements which don’t have thiis attribute defined yet.
Be careful though, and double check before deleting this attribute!