"Inheritor of the ResourceDictionary is expected" - What does this error mean

Question

In App.xaml I have the following code:

<Application
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="FJW.App">
    <Application.Resources>
        <!-- Resources scoped at the Application level should be defined here. -->
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="themes/F4.xaml"/>
                <ResourceDictionary Source="themes/F3.xaml"/>
                <ResourceDictionary Source="themes/F2.xaml"/>
                <ResourceDictionary Source="themes/F0.xaml"/>
                <ResourceDictionary Source="themes/F1.xaml"/>
                <ResourceDictionary Source="themes/Palm.xaml"/>
                <ResourceDictionary Source="themes/Key.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

Visual Studio is finding error in strings <ResourceDictionary Source="themes/...xaml"/> - raising the following error message: Inheritor of the ResourceDictionary is expected.

But the project is getting compiled properly and is working right. What does the error message mean? Maybe it is a bug of this beta Silverlight version? Or is it my error?

Answer 1

Hm. It was a BuildAction problem.

I set up BuildAction property for xamls as Resource. And when I changed this property back to Page - erorrs are vanished.