我成功在私有数据库中创建了一个自定义区域，然后尝试为该自定义区域创建订阅，但是订阅创建失败并显示以下错误：“错误，指示某些项目失败，但操作总体成功。” >

ios文档建议使用CKRecordZonesubscription创建区域订阅。但是我仍然会出错。我该如何解决？

var ContactZonePrivateDb: CKRecordZone  = CKRecordZone(zoneName: Cloud.PrivateZone.Contact.ZoneName)


func createCustomContactInfoZone (completion: @escaping (Error?) -> Void){

    let status = UserDefaults.standard.bool(forKey: Cloud.PrivateDB.CustomZoneCreated)

    if status == true {
        return
    }

    let createZoneGroup = DispatchGroup()
    createZoneGroup.enter()

    let createZoneOperation = CKModifyRecordZonesOperation(recordZonesToSave: [ContactZonePrivateDb],recordZoneIDsToDelete: [] )

        createZoneOperation.modifyRecordZonesCompletionBlock = { (saved,deleted,error) in
            if error != nil  {
                if let ckerror = error as? CKError {
                    self.aErrorHandler.handleCkError(ckerror: ckerror)
                }
                completion(error)
            }
            UserDefaults.standard.set(true,forKey: Cloud.PrivateDB.CustomZoneCreated)
            self.subscribePrivateZoneContact()
            completion(nil)
        }
    createZoneGroup.leave()

    createZoneOperation.qualityOfService = .userInitiated
    self.privateDB?.add(createZoneOperation)
} 

func subscribePrivateZoneContact() {
    let status = UserDefaults.standard.bool(forKey: Cloud.PrivateZone.Contact.SubscriptionID)
    if (status == true) {
        return
    }
    let subscriptionZone = CKRecordZonesubscription(zoneID: ContactZonePrivateDb.zoneID)
    let operation = CKModifySubscriptionsOperation(subscriptionsToSave: [subscriptionZone],subscriptionIDsToDelete: nil)

    operation.modifySubscriptionsCompletionBlock = { saved,error in
        guard error == nil else {
            if let ckerror = error as? CKError {
                self.aErrorHandler.handleCkError(ckerror: ckerror)

            }
            return
        }
        UserDefaults.standard.set(true,forKey:  Cloud.PrivateZone.Contact.SubscriptionID)
        DispatchQueue.main.async {
            print("Successfully added Private zone subscription.\(self.ContactZonePrivateDb.zoneID)")
        }

    }
    operation.qualityOfService = .userInitiated
    self.privateDB?.add(operation)
}