MPMusicPlayer Error Domain=MPErrorDomain Code=4?

Question

I am having issue with Music player, most of the songs gives Error

Error Domain=MPErrorDomain Code=4

The testing device has Apple music subscription and the tracks gives error on the app they are working fine in Apple music app!

Here is the code:

let applicationMusicPlayer = MPMusicPlayerController.systemMusicPlayer()
 applicationMusicPlayer.setQueueWithStoreIDs([ID])

      if #available(iOS 10.1, *)
      {

        applicationMusicPlayer.prepareToPlay { (error) in

            if (error != nil)
            {
                print("[MUSIC PLAYER] Error preparing : \(String(describing: error))")
                return
            }else
            {
                self.start_timer();
                self.applicationMusicPlayer.play()
            }

        }

      }else
      //Play directly ios below version 10.1
      {
        self.applicationMusicPlayer.play()
      }

    }

But what I've tried, when the track gives this error, I went to Apple music player and played it from there its worked, then I came back to my app and play it from my app its worked also fine, so I need to go to Apple music app to play tracks not playing in my app to make them work in my app! That's so weird any idea why?

PS: the testing device has Apple music subscription

Eldaelden

Are the songs that give the error downloaded to the device? Or are they in the users library but not downloaded to the phone? – Marriage

@MicahWilson the songs from remote API , it provide apple songs with epf_id <-- store ID in apple , some are works and most of them are not gives the error above – Eldaelden

But when i go to apple music and play it from there it played , then we i came back to the app and play it from my app its playing also without errors – Eldaelden

I receive the exact same error from similar code. I would recommend opening a radar with Apple about it (I have) as MPMusicPlayerController has been seriously messed up for a while and needs to be fixed. – Mauney

@Mauney i found a solution for this after spending days on it check my question here #46022873 – Eldaelden

Answer 1

I had some similar problems when adding songs to a playlist, solved it by using:

DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(5)) {
    // Code
}

i would play around with waiting a bit before or after preparing.

5 seconds may be too much, but you can start from there

Mikvah