How to debug (step into) BinaryFormatter.Deserialize()?

Question

My app tries to deserialize data sent by client and it fails with the following error:

Exception thrown: \'System.Runtime.Serialization.Serializatio

Answer 1

Without any details i can assume this is compatibility issue with versions of objects you trying to serialize & deserialize. Looks like client sends you some old object bits(without lambda in constructor). And your server running newer version of software searching for some lambda method.

<.ctor>b__0 - is method name for first lambda method in .ctor (object constructor).

So for example if you had on client's machine object A:

class A {
  public A() {
   int a = 5;
   int b = 7;
   // Plain code, no lambdas
  }
}

Then you updated your class on server introducing lambda in constructor:

class A {
  public A() {
   int a = 5;
   int b = 7;
   Func some = x => x * 2 + a; 
  }
}

After that their binary representation is not the same, server version of A has private invisible method <.ctor>b__0 in it.