ISerialization madness

I've just tried your code in Visual Studio in a console application and it works perfectly :-)

From my past experience with Unity, do only use the internal serialization system of Unity.

If you want to serialize a personal object, you can also define a byte array as a public member of a MonoBehaviour. Then just serialize/desarialize to/from this byte array with the binary formatter. Do not implement the ISerialize interface, just use the Serialize attribute it works fine. The byte array itself will be saved by UNity because its a public member.

Here is an example of implementation:

 using System.ComponentModel;
 using ICSharpCode.SharpZipLib.Zip;
 using UnityEngine;
 
 public class NewBehaviourScript : MonoBehaviour 
     {
     // Keep it private instead of public to hide it in the inspector and to other scripts
     [SerializeField, HideInInspector]
         private byte[] m_BackupArray;
     
         private MyClassToSerialize m_MyClassToSerialize;
     
         // Restore your class
         void Awake () 
         {
             RestoreChanges();
         }
     
         public void StoreChanges()
         {
             // Save your class with compression
             var saveStream = new System.IO.MemoryStream();
             using (var stream = new ZipOutputStream(saveStream))
             {
                 stream.PutNextEntry(new ZipEntry("My backup"));
                 var binaryFormatter = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
                 binaryFormatter.Serialize(stream, m_MyClassToSerialize);
                 stream.CloseEntry();
             }
             saveStream.Close();
             m_BackupArray = saveStream.GetBuffer();
         }
     
         public void RestoreChanges()
         {
             if (m_MyClassToSerialize != null)
             {
                 using (var stream = new ZipInputStream(new System.IO.MemoryStream(m_BackupArray)))
                 {
                     stream.GetNextEntry();
                     var binaryReader = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
                     m_MyClassToSerialize = (MyClassToSerialize) binaryReader.Deserialize(stream);
                 }
             } 
             else
             {
                 m_MyClassToSerialize = new MyClassToSerialize();
             }
     
             // One way to keep track of the changes
             m_MyClassToSerialize.PropertyChanged += OnMyClassToSerialize_PropertyChanged;
         }
     
         void OnMyClassToSerialize_PropertyChanged(object sender, PropertyChangedEventArgs e)
         {
             StoreChanges();
         }
     }