CartPage and CheckoutPage throw TargetInvocationException

After adding CartPage and CheckoutPage to my project, I get this error when I attempt to navigate to either of them:

     System.Reflection.TargetInvocationException: 'Exception has been thrown by the target of an invocation.'

The error goes away if I remove this block of code at the top.

     <ContentPage.ControlTemplate>
        <ControlTemplate>
            <StackLayout Spacing="0">
 
                <!--  Title View  -->
                <controls:TitleView Title="Cart" BackgroundColor="{DynamicResource Gray-White}" />
 
                <ContentPresenter />
 
            </StackLayout>
        </ControlTemplate>
    </ContentPage.ControlTemplate>

Visual Studio 2019 16.2.5
Syncfusion 17.2.0.51
Xamarin Forms 4.2.0.815419