TypeSelectorPopupContent brings abstract classes.

[Ricardo Cicaida]

During the construction of the TypeSelectorPopupContent, it searches for all types that inherit from a specific type, but it also allows abstract classes, wich does not make sense, since this popup is used for creating instances of a type.
var types = new List<Type>(); foreach (var validType in validTypes) { types.AddRange(Types.GetAllTypesOf(validType)); }