SerializationException Type “is not marked as serializable” - But it is

Question

In Windows Forms, .NET Framework 4.0, I am trying to Serialize an instance of a class I wrote.

The class is marked as Serializable, but the form that uses the class

Answer 1

[field:NonSerializedAttribute()]
public event EventHandler BrazierCuttoffChanged;

Had the same problem, the PropertyChanged EventHandler of my serializable NotifyObject base class was subscribed by some viewmodels which went into the serialization queue therefore. Adding the NonSerializedAddtribute to this EventHandler saved my day. :-)