Parse platform 上载到解析时Imagepicker崩溃

每当我试图拍摄一张照片作为用户的个人资料图片上传到解析时，我的应用程序总是崩溃。花了好几个小时在网上寻找，但还是弄不明白。请帮忙

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
    let pickedImage: UIImage = info[UIImagePickerControllerOriginalImage] as! UIImage
        let imageData = UIImagePNGRepresentation(pickedImage)
    let imageFile:PFFile = PFFile(data: imageData)
    PFUser.currentUser()!.setObject(imageFile, forKey: "profile_picture")
    PFUser.currentUser()!.saveInBackground()
    picker.dismissViewControllerAnimated(true, completion: nil)
}

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原来文件太大了，我需要缩放它。感谢Bjorn提醒我查看堆栈跟踪

请将堆栈跟踪添加到您的问题中