Cannot deserialize an IComparable field for value types

I have investigated an issue around binary serialization of a IComparable property which causes the following error when the IComparable property is assigned a DateTime: Binary stream '0' does not contain a valid BinaryHeader. The following code can produce this issue: ``` /// <summary> /// This class is injected with an icomparable object, which is assigned to a property. /// If serialized then deserializes using binary serialization, an exception is thrown /// </summary> [Serializable] public class SomeClassNotWorking { public SomeClassNotWorking(IComparable property) { Property = property; } public IComparable Property; } public class Program { static void Main(string[] args) { // var comparable = new SomeClass<DateTime>(DateTime.Today); // here we pass in a datetime type that inherits IComparable (ISerializable also produces the error!!) var instance = new SomeClassNotWorking(DateTime.Today); // now we serialize var bytes = BinaryHelper.Serialize(instance); BinaryHelper.WriteToFile("serialisedResults", bytes); // then deserialize var readBytes = BinaryHelper.ReadFromFile("serialisedResults"); var obj = BinaryHelper.Deserialize(readBytes); } } ``` I have resolved the issue by replacing the IComparable property with a type T property which implements IComparable: ``` /// <summary> /// This class contains a generic type property which implements IComparable /// This serializes and deserializes correctly without error /// </summary> /// <typeparam name="T"></typeparam> [Serializable] public class SomeClass<T> where T : IComparable { public SomeClass(T property) { Property = property; } public T Property; } ``` This serializes and de-serializes without problems. However, why would serialization of an IComparable property (when that property is a DateTime) cause the issue in the first place, particularly as DateTime supports IComparable? This also happens with ISerializable.