How do I load related entities of type IEnumerable

Question

I\'m trying to load related entities of a SingleOrDefault entity, but I am getting the following exception:

The navigation property of type IEnumerable is not a sing

Answer 1

IEnumerable is not supported as a type for a navigation collection. You must use ICollection or another interface derived from it (for example IList) or a concrete implementation of ICollection - like List, HashSet, etc.