Error #2044: Unhandled IOErrorEvent:. text=Error

hello guys, may u help me to tell me whats wrong with this code ?
before i test my project its ok (i using adobe animate 2021), but then when i try open in adobe anime 2022 (for testing other error but not work) so i return using adobe animate 2021. then i try my project then this error out.
Error #2044: Unhandled IOErrorEvent:. text=Error #2032: Stream Error. at multimediainteraktifpurapusertasik_fla::musik_on_2/frame1()[multimediainteraktifpurapusertasik_fla.musik_on_2::frame1:15]

my code:

import flash.events.MouseEvent;
import flash.media.SoundTransform;
stop();

tombol_matikan_musik.addEventListener(MouseEvent.CLICK, fl_ClickToGoToAndStopAtFrame_5);

function fl_ClickToGoToAndStopAtFrame_5(event:MouseEvent):void
{
gotoAndStop(2);
}

var lagu:Sound = new Sound();
lagu.load(new URLRequest("Backsound.mp3"));
var musik:SoundChannel = new SoundChannel();
musik = lagu.play(0,1);

tombol_matikan_musik.addEventListener(MouseEvent.CLICK, atur_tombol_suara);

var suara_aktif:Boolean = true;
var posisi:Number = 0;

function atur_tombol_suara(e:MouseEvent):void
{
var nama_tombol:String = e.currentTarget.name;
nama_tombol == "tombol_matikan_musik";
{
posisi = musik.position;
musik.stop();
suara_aktif = false;
}

}

thnx for help me