Seems that Firefox 52 is the culprit here, having been mentioned in most of the posts so far.
Please note that Mozilla, the distributor of Firefox, is going through some changes, that we'll see & feel first hand. To put it simple, Firefox will soon become another Google Chrome clone, and some of the add-ons has already fell out of support for the browser. Notably, at some point, we'll lose perhaps the best security add-on of any browser in NoScript, as well as the popular download manager Down Them All, yet there'll be more. Eventually will get to the point that add-one will be coming from the Chrome Web Store, just like many of the other Chromium based browsers.
It's already happening under our noses & here's one example (new Firefox add-on) of what I cited above.
Some of the 3rd party extension developers spoke out over the matter, nothing they can do. Once Firefox shipped two back to back Full buggy releases (to include several minor releases), many flocked to Google Chrome & Mozilla lost control of the destiny of Firefox forever. Google seized the moment & won many over with a faster, lesser bug free browser. Sadly for myself, was a long time Firefox user, once IE8 crippled my XP Pro SP3 powered notebook that had a single core CPU & only 2GB DDR2-6400 RAM (it's max), Firefox 3.5 RC was a great browser, breathing new life into it, and for nearly 4 more years, would be my default browser. Mozilla got sloppy with rushed browser upgrades, and paid the price for 'fixing what wasn't broken'.
This has now been in the works for over two years, and now it's users are beginning to see the changes first hand. Here's an article regarding some changes, why some plugins doesn't work, with the option to choose Firefox ESR (usually used by businesses, schools & other places where one must have a stable browser). This will be supported until sometime in 2018.
As to Pulse Audio, it's a native feature of many Linux distros, and sometimes one must really play with the app to make it work, it's not a feature of Firefox.
May be a good idea to go into the Package Manager, type in Pulse Audio & look for any missing recommends, it's a place to start.
Edited by cat1092, 14 March 2017 - 03:48 AM.