I thought it was a simply login failure, so I logged in and the icon went green, as normal. However, I noticed that Hello did not display the "Start a conversation" window, but one that read "browse this page with a friend".
A bit confused, I called Megatotoro, who read this statement from Mozilla to me. Apparently, I had missed the fact that Mozilla is discontinuing Hello starting from Firefox 49. Current Firefox version is 48, so...
Although I did not use the functionality much, I consider that it was convenient and had a lot of potential, in particular when users do not want to use Microsoft's Skype, Google's Handouts, or Facebook chat, I guess.
Mozilla, in its brief statement, thanks Hello supporters and points them to other providers:
"Here are a few alternatives to Hello. We hope you’ll find one you’ll like:
- Talky: Provides both video and screen sharing using WebRTC.
- Cisco Spark: Create rooms for video calling, group messaging and sharing.
- Appear.in: Group video calling for up to eight people.
- Jitsi Meet: Group video calling and screen sharing using WebRTC"
I fear this will be the future of this interesting WebRTC technologies...