Playing with no sound on explorer.

[skajg]

I've implemented a flashhls with mediaelement on my website.
Everything's worked fine since a year ago when it's been built.
Now, I found I couldn't hear any sound from video only on ie browers, even if it plays the video well itself as it was.

It seems there were some amendments on flashplayer.
I've already tested the other PC & different broswers that shows the same results.

Is it already known issue? or does it come forward newly?

In one statement,
Playing well a video without any sounds on ie, all of sudden.