Why does deserialization fail in the web player

I’m running a C# script in Unity 4.0.0f7 and am trying to deserialize a simple class using the DataContractSerializer, but an exception is thrown when run in the Web Player from a browser. This works fine in the Unity editor or when built for PC/Mac platform. The error sounds like the constructor is not accessible, but there is a public, default constructor on the class. I’m guessing that this is some restriction for the Web Player, but the DataContractSerializer isn’t listed in Unity’s Mono Compatiblity list so I don’t know if it is allowed or not.

To use the DataContractSerializer, I copied the System.Runtime.Serialization.dll from the C:\\Program Files (x86)\\Unity\\Editor\\Data\\Mono\\lib\\mono\\unity directory to my Unity project’s Assets\\Plugins directory.

Ultimately, I am trying to deserialize an object that was serialized with the DataContractSerializer and obtained from a restful web service.

A similar question was asked some time ago, but no answer was ever posted.

Update: This problem does not appear to happen if using the XmlSerializer instead of the DataContractSerializer. I tested the same code with the XmlSerializer and it worked fine in the Web Player.

Here’s the code that is failing:

 [DataContract]
 public class Number
 {
     [DataMember]
     public int Int1 { get; set; }
 }
 
 public class TalkRest : MonoBehaviour
 {
     void Start()
     {
         try
         {
             Number num = new Number();
             num.Int1 = 1;
             DataContractSerializer dcs = new DataContractSerializer(num.GetType());
             using (var ms = new MemoryStream())
             {
                 dcs.WriteObject(ms, num);
                 Debug.Log("Number serialized.");
                 ms.Position = 0;
                 Number resultNum = (Number) dcs.ReadObject(ms);
                 Debug.Log(resultNum);
             }
         }
         catch (Exception e)
         {
             Debug.Log("DataContractSerializeTest exception: " + e.Message + ", stack: " + e.StackTrace);
         }
     }
     private void Update() {}
 }

Here’s the exception that is thrown:

 DataContractSerializeTest exception: Attempt to access a private/protected method failed., stack:   at System.Security.SecurityManager.ThrowException (System.Exception ex) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.SerializationMap.DeserializeContent (System.Xml.XmlReader reader, System.Runtime.Serialization.XmlFormatterDeserializer deserializer, Boolean empty) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.SerializationMap.DeserializeContent (System.Xml.XmlReader reader, System.Runtime.Serialization.XmlFormatterDeserializer deserializer) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.SerializationMap.DeserializeObject (System.Xml.XmlReader reader, System.Runtime.Serialization.XmlFormatterDeserializer deserializer) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlFormatterDeserializer.DeserializeByMap (System.Xml.XmlQualifiedName name, System.Type type, System.Xml.XmlReader reader) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlFormatterDeserializer.DeserializeCore (System.Type type, System.Xml.XmlReader reader) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlFormatterDeserializer.Deserialize (System.Type type, System.Xml.XmlReader reader) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlFormatterDeserializer.Deserialize (System.Xml.XmlReader reader, System.Type type, System.Runtime.Serialization.KnownTypeCollection knownTypes, IDataContractSurrogate surrogate, System.String name, System.String ns, Boolean verifyObjectName) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.DataContractSerializer.ReadObject (System.Xml.XmlDictionaryReader reader, Boolean verifyObjectName) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlObjectSerializer.ReadObject (System.Xml.XmlDictionaryReader reader) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.DataContractSerializer.ReadObject (System.Xml.XmlReader reader) [0x00000] in <filename unknown>:0 
   at System.Runtime.Serialization.XmlObjectSerializer.ReadObject (System.IO.Stream stream) [0x00000] in <filename unknown>:0 
   at TalkRest.Start () [0x00000] in <filename unknown>:0 

Thanks in advance!