WHY It don't play notes

It plays sounds when the first day I download , the next few day is still working , but after almost a week , the sound stops playing any more . The metronome is still working but when it plays notes it stop playing like in mute mode. I check the mixture but it not in mute mode . Is this my only problem or other user also have this such problem . Please contact me if you want to help me , I will be felling thankfully for being help even it is not working . THANK YOU.

CONTACT: vegamouse4@gmail.com