Flash content doesn't work at all in firefox 4.01 on my mother's computer. All flash content either is just blank or a solid colored (usually black or white) box. For example on Youtube, the videos just show up as black boxes. On face book the game windows are either blank or a solid colored box. Mostly it is just blank where the flash content should be. Flash works completely fine in Both I.E. and Chrome.
The problems started in the latest version of Firefox 3. The flash pugin container was crashing a lot. Like multiple times in an hour. Then it just stopped working as explained above. After I tired un-installing the flash player and plugins and reinstalling them with out success, I tried upgrading to Firefox 4.01. This didn't fix the problem either so I tried removing the flash player and plugins and re-installing them again. This didn't work so I completely un-installed Firefox 4.01, making sure to delete all the files in the appdata folder as well. Then I un-installed every thing having to do with flash. After this was done I reinstalled Firefox 4.01 and the flash player/plugins. This still did not fix the problem.
I have made sure the firewall is not blocking the plugin container and have even completely disabled it. I have also tried turning off hardware acceleration in the flash player, updating the graphics card drivers, running Firefox in safe mode, making a new Firefox profile, deleting all the cookies,history,cache ect., and using an extension called better privacy (http://netticat.ath.cx/BetterPrivacy/BetterPrivacy
I too have read that page over and over and tested my flash by going to the adobe website and nothing works. I have the latest version of everything, yet nothing I do makes the flash movie work in Firefox. I am a web designer and have never had this problem until recently. The flash movie works in IE, Chrome, Safari and even in Netscape, but not in FF. I've asked no less than a dozen people to test it for me and it doesn't work for them in FF either. The player is visible and the image titles change as if the photos were showing, but the window is blank in FF. It also does not loop continuously, as it should in FF. It does in all the other browsers. The images I've attached are from the test example I was making for my client. As you can see, the left one shows the images just fine in Chrome (and is the same in other browsers. The right side image from FF, clearly shows there is nothing showing within the flash window on that page.
That is caused by hotlink protection on the server.
Firefox doesn't pass the referrer to the Flash plugin and the server refuses to send the image files because of that.
http://lori-h.com/MsDenver/slides/p_0001.jpg GET /MsDenver/slides/p_0001.jpg HTTP/1.1 Host: lori-h.com User-Agent: Mozilla/5.0 (X11; Linux i686; rv:10.0) Gecko/20100101 Firefox/10.0 Accept: text/html,application/xhtml+xml,application/xml;q=
0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip, deflate Connection: keep-alive HTTP/1.1 403 Forbidden Date: Tue, 07 Feb 2012 23:05:01 GMT Server: Apache Content-Length: 347 Keep-Alive: timeout=15, max=98 Connection: Keep-Alive Content-Type: text/html; charset=iso-8859-1