I mostly use Firefox but also use Google Chrome, both of which I keep open at the same time (I log in to Facebook with 2 user names as I play Zynga games on one of them (Google Chrome). However, a couple of months ago videos and Zynga games stopped working when I use Firefox. From googling the problem it seems to be a Shockwave Flash problem. I can get videos and games to work on IE and Safari, but they are much slower and less stable, so I generally prefer Firefox. I have tried all suggestions I have found, including one on PC Advisor which suggests checking if Shockwave is listed more than once as Google Chrome has it's own version. It is listed 3 times, so I have tried disabling/enabling in various ways (eg Chrome enabled the others not and vice versa) but unfortunately it doesn't make any difference. Would appreciate if anyone could advise on this as recently uploaded a video onto Facebook which others can see but I can't (unless I log in to a different browser).
I'm not sure about Shockwave Flash? On my 64-bit system Shockwave player won't play in IE 64-bit but OK in IE 32-bit. Flash player works OK in all browsers. So I'm assuming you mean Flash player. Have a look at how to uninstall Flash completely. Take note to close any programs and browsers that run flash. To re-install Flash either let the browser ask to install it or get the IE and non-IE from here. Scroll down a bit for the 'related download' section for the different versions.
OK, so now I have uninstalled Firefox and Google Chrome, then I re-installed Firefox and re-installed Flash. The Zynga games worked. Then I re-installed Chrome (which has Flash pre-installed) and games work there. Went back to Firefox, games no longer work. So it seems to be a compatibility problem with Chrome. Except that now games aren't working on IE either.
You need to install the IE version of flash player for it to work in Internet explorer( see earlier link). In Chrome disable its own Flash player. Close Chrome and see if flash player works in FireFox. If it does then it's a Chrome problem. Why they call it Shockwave Flash doesn't make sense to me.