Moving Video To Photo Library (Swift)

I'm trying to move a video to the photo library and I'm getting very unhelpful errors. Is there any way to get more detailed error information, or is there some place I can look them up?

I've verified that the movie exists by downloading the app data via devices/xcode and the movie plays fine on my macbook.

I have a full help request on StackOverflow with a link to the project (that it does not let me post here): https://stackoverflow.com/questions/63575539/swift-ios-save-video-to-library

I've tried:

Code Block func saveVideoToLibrary(videoURL: NSURL) {
    PHPhotoLibrary.requestAuthorization { status in
      // Return if unauthorized
      guard status == .authorized else {
        print("Error saving video: unauthorized access")
        return
      }
      PHPhotoLibrary.shared().performChanges({
        PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL as URL)
      }) { success, error in
        if !success {
          print("Error saving video: \(String(describing: error))")
        }
      }
    }
  }

with Error: Error saving video: Optional(Error Domain=PHPhotosErrorDomain Code=-1 "(null)")

and

Code Block 
UISaveVideoAtPathToSavedPhotosAlbum(
            videoPath,
            self,
            #selector(self.video(_:didFinishSavingWithError:contextInfo:)),
            nil)

with Error:
Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo= ...... {Error Domain=com.apple.photos.error Code=42001 "(null)"

both compile fine and are called. But end up giving me errors that do not help in the slightest.