System.Exception Sequence contains no matching element

[SethJustus]

Hi, could someone explain why this throws an exception during compilation?

using ReactiveUI;
using ReactiveUI.Fody.Helpers;

namespace ClassLibrary1
{
	public class MessageBase : ReactiveObject
	{

	}
	public class ResponseFirmwareVersion : MessageBase
	{
		private byte AutoCycleFlag { get; set; }
		
		[Reactive]
		public bool AutoCycleFlagEnabled
		{
			get
			{
				return (AutoCycleFlag != 0);
			}
			set
			{

			}
		}
	}
}