DataContractSerializer Error using Entity Framework 4.0 with WCF 4.0

This was a pain to figure out but it is because EntityFramework creates a ‘proxy’ of your class. The TestObject class I had was setup correctly, but it was creating a class called: TestObject_240F2B681A782799F3A0C3AFBE4A67A7E86083C3CC4A3939573C5410B408ECCE

To make the ChannelFactory + WCF + Entity Framework all work together, you must go into your Context constructor and add the following:

ContextOptions.ProxyCreationEnabled = false;