I recently clicked the downloaded button your Firefox Browser for Mac on my iMac. The Window saying it was downloading was still on hours later. Assuming that download had failed I clicked the download button again. The same thing happened twice more til I ended up with 4 icons on my desktop. When I clicked them open all I got was a window identifying Firefox. Finally I searched my finder for Firefox and found 4 links. I clicked one and got a window telling me how to an app that would actually open the browser. That worked and I used the browser for a few days but my computer froze and I had to shut it down without closing my active apps. When I turned my computer on again the opening app was no longer on my desktop. I had to run a search and go through a number of hurdles to get your opening icon back on my desktop. I now need to be find a way to turn my computer off and have the opening icon on my desktop when I turn it back on again. If I had been able to find a phone number for Mozilla Support I could have saved many frustrating hours.