Xamarin Forms 3.3.0 error: No property, bindable property or event found for UWP

I met strange error for UWP from following xaml:

<ContentPage.ToolbarItems>
    <ToolbarItem Text="{Binding [SelectData]}" Command="{Binding AddNewDataCommand}">
      <ToolbarItem.Icon>
        <OnPlatform x:TypeArguments="FileImageSource" iOS="data.png" UWP="Assets/data.png"/>
      </ToolbarItem.Icon>
    </ToolbarItem>
    ...
</ContentPage.ToolbarItems>

When compile, I got:

No property, bindable property, or event found for 'UWP', or mismatching type between value and property.

Why ?