Kod:
ICriteria criteria = session.CreateCriteria<Unit>()
.CreateAlias("UnitContext", "uc").CreateAlias("uc.Name", "ContextName")                    .SetFetchMode("UnitContext", FetchMode.Join);

return criteria.List<Unit>();

Błąd:
NHibernate.QueryException: not an association: Name

Klasy:
    public class Unit
    {
        public virtual int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual string ShortName { get; set; }
        public virtual Context UnitContext { get; set; }
    }

    public class Context
    {
        public virtual int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual IList<Unit> Units { get; set; }
    }

Mapowania:
    public class UnitMap : ClassMap<Unit>
    {
        public UnitMap()
        {
            Id(x => x.Id);
            Map(x => x.Name).Column("name");
            Map(x => x.ShortName).Column("short_name");
            References(x => x.UnitContext, "context_id").Cascade.None();
        }
    }

    public class ContextMap : ClassMap<Context>
    {
        public ContextMap()
        {
            Id(x => x.Id);
            Map(x => x.Name);
            HasMany(x => x.Units).KeyColumn("context_id").Inverse().Cascade.All();
        }
    }