Я сам не знаю как и что, но оно работает как то

mROA.Cbor/CborSerializationToolkit.cs

@@ -183,7 +183,7 @@ namespace mROA.Cbor
                     if (type == typeof(ulong))
                         return reader.ReadUInt64();
 
-                    return reader.ReadInt32();
+                    return reader.ReadUInt64();
                 case CborReaderState.ByteString:
                     if (type == typeof(Guid))
                         return new Guid(reader.ReadByteString());
@@ -284,6 +284,7 @@ namespace mROA.Cbor
 
         private object ReadObject(CborReader reader, Type type, IEndPointContext? context)
         {
+            
             if (type == typeof(object))
             {
                 return new PreParsedValue(ReadList(reader, null, context) as List<object>);
@@ -311,12 +312,13 @@ namespace mROA.Cbor
 
         private void FillObject(object obj, Type type, CborReader reader, IEndPointContext? context)
         {
+            var propertyInfos = type.GetProperties();
+            var properties = FilterProperties(propertyInfos);
+
+            var length = reader.ReadStartArray();
             try
             {
-                var propertyInfos = type.GetProperties();
-                var properties = FilterProperties(propertyInfos);
 
-                var length = reader.ReadStartArray();
 #if TRACE
                 Console.WriteLine($"Reading list of {length} objects, {properties.Count} properties found");       
 #endif
@@ -342,7 +344,7 @@ namespace mROA.Cbor
         public static List<PropertyInfo> FilterProperties(PropertyInfo[] properties)
         {
             var finalProperties = new List<PropertyInfo>(properties.Length);
-            foreach (var property in properties)
+            foreach (var property in properties.Where(i => i.CanWrite && i.CanRead))
             {
                 if (property.GetCustomAttribute<SerializationIgnoreAttribute>() == null)
                     finalProperties.Add(property);

mROA.Cbor/PreParsedValue.cs

@@ -5,13 +5,18 @@ using mROA.Implementation;
 
 namespace mROA.Cbor
 {
-    public class PreParsedValue
+    public interface IPreParsedValue
     {
-        public List<object> Properties { get; set; }
+        object? ToObject(Type type, IEndPointContext? context);
+    }
+
+    public class PreParsedValue : IPreParsedValue
+    {
+        private List<object> _properties { get; set; }
 
         public PreParsedValue(List<object> properties)
         {
-            Properties = properties;
+            _properties = properties;
         }
 
         public object? ToObject(Type type, IEndPointContext? context)
@@ -24,14 +29,31 @@ namespace mROA.Cbor
             {
                 sharedObject.EndPointContext = context;
             }
-            
+
             var properties = CborSerializationToolkit.FilterProperties(type.GetProperties());
             for (var index = 0; index < properties.Count; index++)
             {
                 var property = properties[index];
-                property.SetValue(instance, Properties[index]);
+                property.SetValue(instance, _properties[index] is IPreParsedValue ppv ? ppv.ToObject(property.PropertyType, context) : _properties[index]);
             }
+
             return instance;
         }
     }
+
+    public class ParsedValue : IPreParsedValue
+    {
+        public ParsedValue(object? value)
+        {
+            _value = value;
+        }
+
+        private object? _value;
+
+
+        public object? ToObject(Type type, IEndPointContext? context)
+        {
+            return _value;
+        }
+    }
 }