Does your network require proxy support? Could you try downloading the appropriate installer from this FAQ and give it another try?
I don’t remember which Forum reply where I found the direct link (below) to these two downloads (below) for Firefox, but I downloaded both files and installed FlashPlayer from the Plug-in .msi file.
FlashPlayer for Firefox:
Although I don’t use IE, I had already downloaded and installed the IE version of FlashPlayer from my company’s download site, so I installed the Plug-in version for Firefox. I first manually uninstalled the 10.3.183.5 version, then installed the.msi file for the 10.3.183.10 version. It installed completely and Flash is now working properly with Firefox.
Thanx for the assistance.
Using the above link that was posted by jwhittenton was enough to work for me. I had the same issue with the actionlist not found error for Firefox.