as stated above. i have already done that, several times. the only time flash player doesnt work is for candy crush and 2 other games.
Candy Crush uses both Flash and Shockwave.
Use the Flash Player Uninstaller to remove Flash Player.
Use the Shockwave Player Uninstaller to remove Shockwave as well.
Reset Firefox. (Uninstalling alone will often leave your Profile folder which DOESN'T change anything)
Download the Flash Player FULL installer: Flash Player Plug-in (All other browsers) and run it.
Download the Shockwave Player 12 FULL Installer and run it to replace the Shockwave for Firefox.
You should be good to play after that.