型 'EventToReactiveCommand' の値は、型 'TriggerActionCollection' のコレクションまたは辞書に追加できません。

型 'EventToReactiveCommand' の値は、型 'TriggerActionCollection' のコレクションまたは辞書に追加できません。

<Window x:Class="TestEventToReactiveCommand.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:prism="http://prismlibrary.com/"

        xmlns:behaviours="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:interactivity="clr-namespace:Reactive.Bindings.Interactivity;assembly=ReactiveProperty.WPF"

        xmlns:local="clr-namespace:TestEventToReactiveCommand"
        prism:ViewModelLocator.AutoWireViewModel="True"
        Title="{Binding Title}" Height="350" Width="525">

    <behaviours:Interaction.Triggers>
        <behaviours:EventTrigger EventName="MouseMove">
            <interactivity:EventToReactiveCommand Command="{Binding MouseMoveCommand}">
                <local:MouseMoveToMousePositionConverter />
            </interactivity:EventToReactiveCommand>
        </behaviours:EventTrigger>
    </behaviours:Interaction.Triggers>

    <Grid>
        <ContentControl prism:RegionManager.RegionName="ContentRegion" />
        <TextBlock
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Text="{Binding Message.Value}" />
    </Grid>
</Window>