RecordRTC demos reject to work with firefox

[eugen0329]

Demo url - https://www.webrtc-experiment.com/RecordRTC/AudioVideo-on-Firefox.html
Firefox - 50.1.0
OS - Ubuntu 16.04.1 LTS

Steps:

1. Open https://www.webrtc-experiment.com/RecordRTC/AudioVideo-on-Firefox.html page
2. Click Record Audio+Video
3. Click Share selected devices (camera and mic)

Expected
Recording begins.

Got
Popup with "{}" text and "Ok button"

With Chromium 55.0.2883.87 everything works great.

[vrajroham]

Hey @eugen0329,
It's your hardware issue.
I reproduced using same steps given by you and it works fine.
Issue occured (as yours) when I disconnected webcam from computer and run the demo.

Following would help:
While allowing hardware (if there are multiple devices (camera/microphones) then try to select randomly)
Hope it works for you.

[eugen0329]

I suppose, the problem was with my Firefox. I have just reinstalled it and everything began to work.