Serialization Problem help please

[Arjay]

It si because serialization of generics are gliched. To overcome it, you have to implement ISerializable interface, but in your case, it should be sufficient to change the type of the collection from List<Customer> to Customer[] for the serialization.

Yes, rather than deriving your class from List<Customer>, just make a private List<Customer> field, and expose it as a Customer[] property using List<>.ToArray() and List<>.SetRange().