It seems that a List object cannot be stored in a List variable in C#, and can\'t even be explicitly cast that way.
List sl = new List
I have a:
private List Leerlingen = new List();
And I was going to fill it with data collected in an List
What finally worked for me was this one:
Leerlingen = (List)_DeserialiseerLeerlingen._TeSerialiserenObjecten.Cast();
.Cast
it to the type you want to get an IEnumerable
from that type, then typecast the IEnemuerable
to the List<>
you want.