Erro "ensure event failed"

Quando vou criar um novo evento no ItemTapped me aparece este erro, e não consigo fazer nem de forma manual.

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:TestDrive"
             x:Class="TestDrive.MainPage">

    <ListView x:Name="listViewVeiculos" ItemsSource="{Binding Veiculos}" ItemTapped="" Margin="25">
        <ListView.ItemTemplate>
            <DataTemplate>
                <ViewCell>
                    <ViewCell.View>
                        <StackLayout Orientation="Horizontal">
                            <Label Text="{Binding Nome}" FontSize="20" VerticalTextAlignment="Center"></Label>
                            <Label Text=" - " VerticalTextAlignment="Center"></Label>
                            <Label Text="{Binding PrecoFormatado}" VerticalTextAlignment="Center"></Label>
                        </StackLayout>
                     </ViewCell.View>
                </ViewCell>
            </DataTemplate>
        </ListView.ItemTemplate>   
    </ListView>

</ContentPage>