dotnet-core/release-notes/3.0/preview/api-diff/preview4/3.0-preview4_System.Runtime.Serialization.md

System.Runtime.Serialization

 namespace System.Runtime.Serialization {
+    public sealed class DeserializationBlockedException : Exception {
+        public DeserializationBlockedException();
+        public DeserializationBlockedException(Exception innerException);
+        public DeserializationBlockedException(string message);
+    }
 }