Font loading Issue

Hi,

I'm receiving the following error on Android and I'm unclear as to what to check : E/FontFamily(24205): Error mapping font file Fonts/Montserrat-Light.otf

I've verified that the font is an AndroidAsset, in the folder, and can be read using the following:
var font = Typeface.CreateFromAsset(Assets, "Fonts/Montserrat-Light.otf");

I think I might be doing something wrong in my App.Xaml:

<OnPlatform x:Key="FontLight" x:TypeArguments="x:String">
<On Platform="iOS" Value="Montserrat-Light" />
<On Platform="Android" Value="Fonts/Montserrat-Light.otf" />
</OnPlatform>

And the control I'd like to style:

<Style x:Key="TransparentEntry" TargetType="control:TransparentEntry">
<Setter Property="TextColor" Value="{StaticResource Purple}" />
<Setter Property="FontSize" Value="{StaticResource Small}" />
<Setter Property="FontFamily" Value="{StaticResource FontLight}" />
<Setter Property="BackgroundColor" Value="LightSkyBlue" />
</Style>

The behavior in the UI is that the carot is available but typing is blank. Any guidance would be appreciated.