one to many throw Batch update returned unexpected row count from update

[yuzhaoMR]

//table CustomerArchives public virtual IList<Evaluation> Evaluations { get; protected set; } // Relationships HasMany(x => x.Evaluations).Inverse().Cascade.All();

//table Evaluation public virtual CustomerArchives CustomerArchives { get; protected set; } // Relationships References(x => x.CustomerArchives);

I think there is no problem I wrote.but throw exception "Batch update returned unexpected row count from update". please help me