Hi Firefox users! You Might want to read this!
Recently, I've noticed that a whole bunch of Firefox users have been complaining about duolingo not working so hot on Firefox. Last night, Mozilla (the company that developed firefox) issued a major update to their browser. The update makes the browser faster and more user-friendly. (Don't worry, I've tested it myself.) My point is that the faster browser does make duolingo faster and less glichy. I have noticed that I haven't experienced an Error 404 message for almost a day. (That's pretty good compared to Safari and Chrome.) Hope this helps! Enjoy!
Maybe, an update of Firefox will help
Duolingo only supports the microphone in the Google Chrome browser and in the Apps.