How to fix the 66671 AudioQueueInternalNotifyRunning error when playing a sound?

I'm writing an application in Swift, and I believe the code is all valid, as there are no compiler errors. When I try to play an audio file that I know exists, I get the error listed below.

No audio plays.

I have tried writing the code different ways, including instantiating the AVAudioPlayer with the contentsOf argument.

import UIKit
import CoreML
import AVFoundation

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        let soundURL = Bundle.main.url(forResource: "beep", withExtension: "mp3")!
        var soundPlayer : AVAudioPlayer!
        do {
            soundPlayer = try AVAudioPlayer(contentsOf: soundURL)
        }
        catch {
            print("Err")
        }
        soundPlayer.play()


    }

}

Here is the error:

    2019-10-18 22:35:29.609690-040 Test[. . .] [plugin] 
AddInstanceForFactory: No factory registered for id <CFUUID . . . > . . 

   2019-10-18 22:35:30.527132-0400 ML Test[19542:1516755] [aqsrv] AQServer.cpp:68:APIResult: Exception caught in AudioQueueInternalNotifyRunning - error -66671