VS 2013 design time error ResourceDictionary ModernUI.xaml

Dec 3, 2013 at 2:48 PM
The sources defined in step 5 on this page:
it give an error at design time in VS 2013.
Error Value cannot be null.Parameter name: item
If I change it to:
<ResourceDictionary Source="pack://application:,,,/FirstFloor.ModernUI;component/Assets/ModernUI.xaml"/>
I get the same error.
As far as I know this does not happen in VS 2012
If someone here has overcome this issue please post a reply, thanks !
Dec 6, 2013 at 4:34 AM

I'm using VS 2013 ultimate, app.xaml Resource Dictionary looks like below, and it works.

<ResourceDictionary Source="/FirstFloor.ModernUI;component/Assets/ModernUI.xaml" />