Receive kAUGraphErr_CannotDoInCurrentContext when you call AUGraphStart and play

The error occurred when we tried to use, AUGraphStartque is for a reproduction (audio) the code I have is this:

(BOOL)startRendering{
    if (playing) {
        return YES;
    }

    playing = YES;

    if (NO == [self setupAudioForGraph:&au_play_graph playout:YES]) {
        print_error("Failed to create play AUGraph",0);
        playing = NO;
        return NO;
    }

    //result = kAUGraphErr_CannotDoInCurrentContext (-10863)
    OSStatus result = AUGraphStart(au_play_graph);
    if (noErr != result) {
        print_error("AUGraphStart", result);
        playing = NO;
    }

    return playing;
}

This result code is only a transient state, which will pass as soon as the call of your other thread is completed to AUGraph (which has the block). How can I debug the case and what could be the potential problem here?