尝试使用谓词从核心数据swift 3获取不同的行时发生崩溃

Question

我正在尝试从核心数据中获取不同行的数组，我正在尝试下面的代码。

func fetchDataFromLocalDB() {

    if #available(iOS 10.0, *) {
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        let managedContext = appDelegate.persistentContainer.viewContext

        let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Session_Subjects")
        let predicate = NSPredicate(format: "dmode_id == %@", "\(User.deleveryMode)")

        request.resultType = .dictionaryResultType
        request.propertiesToFetch = ["subject_id"]
        request.returnsDistinctResults = true
        request.predicate = predicate
        do{ 

// Here my app is crashing
            arrResultSubject = try managedContext.fetch(request) as! [Session_Subjects] 

        }
        catch  {
            // print(eror)
        }

    } else {
        // Fallback on earlier versions
    }
    //For data fetch in coredata

    let sectionIndex = IndexSet(integer: 0)
    self.tableSubjectView.reloadSections(sectionIndex, with: .automatic)

}

但是当我在[Session_Subjects]上面分配值是coredata类的数组时，我会崩溃。

提前感谢。