Inspection: False "Field ... is never assigned" error

I'm using R# 8 and the following code produces two false errors:
"Field 'dwTime' is never assigned" and "Field 'cbSize' is assigned but its value is never used".

    public static class User32
    {
        private struct LASTINPUTINFO
        {
            public uint cbSize;
            public uint dwTime;
        }
 
        [DllImport("user32.dll")]
        static private extern bool GetLastInputInfo(ref LASTINPUTINFO lii);
 
        public static TimeSpan InputIdleTimeSpan
        {
            get
            {
                var info = new LASTINPUTINFO();
                info.cbSize = Convert.ToUInt32(Marshal.SizeOf(info));
                if (!GetLastInputInfo(ref info))
                    throw new InvalidOperationException("Failed to read the last input time.");
 
                var environmentTickCount = Convert.ToUInt32(Environment.TickCount);
                var lastInputTicks = environmentTickCount - info.dwTime;
                TimeSpan timeSpanFromTicks = TimeSpan.FromTicks(lastInputTicks * 10000);
                return timeSpanFromTicks;
            }
        }
    }