
notification Channel이 등록되지 않았을 경우 발생하는 오류라고 합니다.
public void createNotificationChannel() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationManager manager = getBaseContext().getSystemService(NotificationManager.class);
NotificationChannel serviceChannel = new NotificationChannel(
channelId,
channelname,
NotificationManager.IMPORTANCE_NONE
);
manager.createNotificationChannel(serviceChannel);
}
}