I am receiving the following error:
System.InvalidOperationException was unhandled Message=The type \'Judge\' is not attributed with EdmEntityTypeAtt
I had a similar problem - it seems that in some cases (for example, when using WCF Data Services 5.2.0), it's a problem to have code-first/DbContext classes in the same assembly as EDMX/model-first/generated classes. For me, moving the DbContext classes into a separate assembly fixed the problem.
Note that I didn't have a problem with code-first + model-first in the same assembly when just accessing the DB. But as soon as I added another layer (WCF Data Services) I ran into the EdmSchemaAttribute error.