The version of flash player that you installed may not match the version needed for the games you are attempting to load on facebook. I would imagine that if you installed the latest version from the official adobe flash website (there are plenty of nasty websites out there that want to trick people and install something that is really not adobe flash) there should not be a problem.

My recommendation is to go to the offical website for adobe, find the download link for the latest flash player, and try reinstalling it. If that does not work please do let people know what operating system you are using--Windows? Mac? Linux?, what version of flash you are using, and what version of firefox you are using as they are all relevant in diagnosing flash problems.

hello, you could also try it with the download from https://helpx.adobe.com/flash-player/kb/installation-problems-flash-player-windows.html#main-pars_header