iOs 9b - Audio device xx error sample rate is 0.

Hello, I just fired up XCode 7 and iOS9. Launched my app Thailes (id889292455) in the simulator, which plays a tune when loaded. I get jagged audio and a neverending stream of messages in the log that look like this:

2015-07-02 13:01:25.164 Thailes[1791:423977] 13:01:25.164 ERROR:>aqme> 299: Audio device 0x46: error '!obj' fetching sample rate, or sample rate is 0. Defaulting to 44100.
2015-07-02 13:01:25.165 Thailes[1791:423977] 13:01:25.165 ERROR:210: EXCEPTION thrown ('!dev'): error != 0
2015-07-02 13:01:25.165 Thailes[1791:423977] 13:01:25.165 ERROR:752: Can't make UISound Renderer
2015-07-02 13:01:25.203 Thailes[1791:423998] 13:01:25.203 ERROR:>aqme> 299: Audio device 0x4f: error '!obj' fetching sample rate, or sample rate is 0. Defaulting to 44100.
2015-07-02 13:01:25.203 Thailes[1791:423998] 13:01:25.203 ERROR:210: EXCEPTION thrown ('!dev'): error != 0
2015-07-02 13:01:25.206 Thailes[1791:423998] 13:01:25.206 ERROR:>aqme> 299: Audio device 0x55: error 'who?' fetching sample rate, or sample rate is 0. Defaulting to 44100.

I'm using this code (this is consolidated) where the sound is created, faded in and set to loop

_sound = [[AVAudioPlayer alloc] initWithContentsOfURL:URL error:NULL];

- (void)fadeTo:(float)volume duration:(NSTimeInterval)duration
{
    _startVolume = [_sound volume];
    _targetVolume = volume * _baseVolume;
    _fadeTime = duration;
    _fadeStart = [[NSDate date] timeIntervalSinceReferenceDate];
    if (_timer == nil)
    {
        self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0/60.0
                                                      target:self
                                                    selector:@selector(tick)
                                                    userInfo:nil
                                                     repeats:YES];
    }
}

- (void)tick
{
    NSTimeInterval now = [[NSDate date] timeIntervalSinceReferenceDate];
    float delta = (float)((now - _fadeStart)/_fadeTime * (_targetVolume - _startVolume));
    [_sound setVolume:(_startVolume + delta) * _baseVolume];
    if ((delta > 0.0f && [_sound volume] >= _targetVolume) ||
        (delta < 0.0f && [_sound volume] <= _targetVolume))
    {
        [_sound setVolume:_targetVolume * _baseVolume];
        [_timer invalidate];
        self.timer = nil;
        if ([_sound volume] == 0.0f)
        {
            [self stop];
        }
    }
}

[_sound setNumberOfLoops:looping? -1: 0];

Finally this is derived from a Sound Class I installed in my app called SoundManager, nick lockwood here it is on github:

github+com/nicklockwood/SoundManager - trouble getting posts to show with real links. replace the + with a .