如何修复错误'；在-executePlan中失败：错误coreml'；在Xcode中？

当我启动下面的代码时，我在-executePlan:error:'中得到了错误'[coreml]Failure'。 我会尝试在CoreML上执行我的CNN模型。我用python上的coremltools制作了CNN模型

Mac:macOS BigSur 11.4.
Xcode:12.0.
CNN架构：输入conv2d_6_输入图像（颜色130*130），输出多阵列（浮点32）

谢谢你抽出时间

import UIKit
import CoreML
import Vision
import ImageIO

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    guard let image = UIImage.init(named: "R-1-NW-60_0_3") else{ return }
    guard let cgImage = image.cgImage else { return }
    //guard let cvpImage =  image.pixelBuffer() else {
    //    return
    //}

    guard let model = try? VNCoreMLModel(for: NewCNN().model) else {
                assertionFailure("Error: CoreML")
                return
    }
    
    let classificationRequest = VNCoreMLRequest(model: model) {
      request, error in
      if let observations = request.results as? [VNClassificationObservation] {
        /* do something with the prediction */
        print(observations)
      }
    }

    let handler = VNImageRequestHandler(cgImage: cgImage)
    try? handler.perform([classificationRequest])
}

}