I am facing an error in v4.1, while I add navigation property in Customer Table using another partial class
"Navigation property 'Addresses' on entity type 'Customer' is not virtual. UseLazyLoadingProxies requires all entity types to be public, unsealed, have virtual navigation properties, and have a public or protected constructor"
// this is the collection I added with foreign reference
protected ICollection<UserFriend> _userFriends;
public virtual ICollection<UserFriend> UserFriends
get => userFriends ?? (userFriends = new List<UserFriend>());
protected set => _userFriends = value;