When the DTO has both Guid and List as properties, serializer only serializes the List<> and omits Guid property completely. Trying to de-serialize such data results in a nasty nasty exception:

Managed Debugging Assistant 'FatalExecutionEngineError' has detected a problem in C:\blabla\bin\Debug\Serializers.vshost.exe.

Additional information: The runtime has encountered a fatal error. The address of the error was at 0xdf24bc2a, on thread 0x3a40. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.

Short sample code:

Dto

public class SimpleItem { public Guid Id { get; } public List<int> Ints { get; } public SimpleItem(Guid id, List<int> ints) { Id = id; Ints = ints; } }

Serialization

var context = new SerializationContext(); var serializer = context.GetSerializer<SimpleItem>(); var item = new SimpleItem(Guid.NewGuid(), new List<int>() { 5, 11 }); var serializedItem = serializer.PackSingleObject(item); var deserializedItem = serializer.UnpackSingleObject<SimpleItem>(serializedItem );

Using this stupid code snippet, serializedItem is only 4 bytes long, which contains only the List and Guid prop is not there. Trying to unpack causes the exception above.

Now what I found is IF we modify the Guid Id {get;} property to have a public setter:

public Guid Id { get; set; }

Then everything works as expected and data is packed and unpacked correctly. And its weird cause setter makes PACKING not to break anymore...

I tried a few other combinations:

Works

public class SimpleItem { public Guid Id { get; set } public List<int> Ints { get; set } }

Does NOT work*

public class SimpleItem { public readonly Guid Id; public List<int> Ints { get; } public SimpleItem(Guid id, List<int> ints) { Id = id; Ints = ints; } }

Works

public class SimpleItem { public Guid Id { get; } public SimpleItem(Guid id) { Id = id; } } `` **Works** ```cs public class SimpleItem { public List<int> Ints { get; } public SimpleItem(List<int> ints) { Ints = ints; } }

Works

public class SimpleItem { public Guid Id { get; } public JustInts Ints { get; } public SimpleItem(Guid id, JustInts ints) { Id = id; Ints = ints; } } public class JustInts { public List<int> Ints { get; } public JustInts(List<int> ints) { Ints = ints; } }

Does NOT work. Messes up completely and debugger shows Id field as List and Ints field is null*

public class SimpleItem { public string Id { get; } public List<int> Ints { get; } public SimpleItem(string id, List<int> ints) { Id = id; Ints = ints; } }

Same as above...

public class SimpleItem { public long Id { get; } public List<int> Ints { get; } public SimpleItem(long id, List<int> ints) { Id = id; Ints = ints; } }

So as it seems as long as Guid (or some other primitive type) and List are at the same level (class), and Guid property does not have a public setter, something wrong happens.

I have not tried other collection types instead of List.