Retail_manager/RMWPFUserInterface/App.xaml

<Application x:Class="RMWPFUserInterface.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:RMWPFUserInterface">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary>
                    <local:BootStrapper x:Key="Bootstrapper" />
                </ResourceDictionary>
            </ResourceDictionary.MergedDictionaries>
            <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
        </ResourceDictionary>
    </Application.Resources>
</Application>