Receiving kAUGraphErr_CannotDoInCurrentContext when calling AUGraphStart for playback

You can make something out of CSS or SQLite. This is why

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

return playing;

}

Try to just manipulate this code, there is a problem with Booleans in your code…