Q: Xamarin forms creating Value Converter causing ResolveLibraryProjectImports task to fail I have created the following converter
public class StringToNullableInt : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (string.IsNullOrEmpty(value.ToString()))
        {
            return null;
        }
        else
        {
            int tmp = 0;
            if (Int32.TryParse(value.ToString(), out tmp))
            {
                return tmp;
            }
            else
            {
                return null;
            }
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, string language)
    {
        return value.ToString();
    }
}

However this causes any attempt to build the android app to error out saying 
The "ResolveLibraryProjectImports" task failed unexpectedly.
System.IO.FileNotFoundException: Could not load assembly 'Windows.winmd, Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile?
It's not even used or referenced anywhere yet. If I stop inheriting the IValueConverter everything builds fine. 

A: I think you might have referenced the wrong IValueConverter. Make sure that it is in the Xamarin.Forms.IValueConverter namespace (see the Xamarin.Forms documentation here) and not in the Windows namespace (see documentation here).
