Something is wrong. I don't see our class audio file today on the page. There is only one audio file whose duration is 35 seconds. I really want to listen to today's class again!

Dong-hoon.  I am not certain why you cannot retrieve an audio file of today's class.  I did nothing to disable the audio feture; I never touch any controls that would change the audio.  You may want to call your student representative and mention that you are having a technical issue, and see how that person can assist you.  Sorry for the problem; I have no idea why this occurred.    Lucky

Additional note:  Dong-hoon, I did listen to your class audio and for me it was also only a 35 second recording.  I then listened to the audio of another student's class, and the entire class session had been recorded and was available to be heard.  This leads me to conclude that the system that I am using is properly working.  Beyond that, I have not thoughts, because as you are aware, I am not a technical whiz.  So, you may have to trouble-shoot the issue with your student representative.  Thanks, Dong-hoon.