Corrected UniqueId implementation.

Thanks @Anaminus!

Tokens/UniqueId.cs

@@ -1,9 +1,10 @@
 using System;
 using System.Xml;
+using RobloxFiles.DataTypes;
 
 namespace RobloxFiles.Tokens
 {
-    public class UniqueId : IXmlPropertyToken
+    public class UniqueIdToken : IXmlPropertyToken
     {
         public string XmlPropertyToken => "UniqueId";
 
@@ -13,7 +14,13 @@ namespace RobloxFiles.Tokens
 
             if (Guid.TryParse(hex, out var guid))
             {
-                prop.Value = guid;
+                var bytes = guid.ToByteArray();
+                var random = BitConverter.ToUInt64(bytes, 0);
+
+                var time = BitConverter.ToUInt32(bytes, 8);
+                var index = BitConverter.ToUInt32(bytes, 12);
+
+                prop.Value = new UniqueId(time, index, random);
                 return true;
             }
 
@@ -22,7 +29,18 @@ namespace RobloxFiles.Tokens
 
         public void WriteProperty(Property prop, XmlDocument doc, XmlNode node)
         {
-            var guid = prop.CastValue<Guid>();
+            var uniqueId = prop.CastValue<UniqueId>();
+            var random = BitConverter.GetBytes(uniqueId.Random);
+
+            var time = BitConverter.GetBytes(uniqueId.Time);
+            var index = BitConverter.GetBytes(uniqueId.Index);
+
+            var bytes = new byte[16];
+            random.CopyTo(bytes, 0);
+            time.CopyTo(bytes, 8);
+            index.CopyTo(bytes, 12);
+
+            var guid = new Guid(bytes);
             node.InnerText = guid.ToString("N");
         }
     }