I have been using Firefox 32 bit for years, on Windows 10 for almost a year. I spend a lot of time (most of every weekday) with Google Finance open, looking at specific stocks. One example would be NFLX (https://www.google.com/finance?q=NASDAQ%3ANFLX&ei=Zg1pWaDgFJCBmAHjx474DA). The graph on that page uses Adobe Flash. This was all working fine until today, after I updated Firefox to the 64 bit version. Now when I have that sort of Google Finance page open, Firefox eventually hangs telling me that the Flash plug-in is at fault. I have to take the choice to kill the add-in to get control of Firefox back. I tried updating Adobe Flash, but that changed nothing. Possibly because I spend most of my time on another tab, all these failures occur when Google Finance is on an inactive tab.