YOU stated that you had this problem before and that it "Randomly" started to work again which in all honesty is a HEAVY indication the issue is on YOUR END, thus the reply I gave you initially. Maybe you had a different pc but same headset? Is that headset usb ? Does it use it's own drivers? Do you use a mic only and hear people via your speakers and is that mic usb and with it's own drivers ? This stll the same pc with which you had the issue with before? There are tons of questions but frankly that still falls a bit on USER end especially since YOU (user) updated to win10 which I will say to you from personal experience that's been a mixed bag for me.
Start by running a google search of the basic symptoms, I am also a windows 10 adopter as I said and with google's help I found a few post about my own issue with win 10 and apps. I had similar issues where my sound would fully stop if I was using anything but the default speakers on my laptop. So I thought HEY maybe just maybe it's my end. Oddly enough windows 10 was randomly causing issues with my headset's drivers so on my end I fixed it by just un-istalling the particular drivers for my headset and letting it windows use the default for my system, this problem affected SL as well but hey I fixed and did not go the extreme of threats to stop using an app? Come on! It is not LL's responsibility to cater to every single set up or create a particular build for 5903902733 possible pc configurations. Users have a certain amount of responsibility when it comes to their own hardware.
Curiosity got the best of me and I looked at your previous topic and it seems that then too you had a notion to blame the viewer in that case it was a 3rd party viewer. So I will beckon to ask again, are you using a USB headset/mic? Honestly though you cannot always blame software even if you think you tried all you can with the software, our hardware or equipment/accessories can be just as much at fault.
One last thing, you are better off providing a DX DIAG not your order form details.....here let me help you...
Run Dx Diag Windows 10