You have to use an older version of Flash, the current one wont work.
I have this version for you here on my link belowhttp://tinyurl.com/86wlddj>
Once downloaded if it doesn't unzip automatically then double click on that file.
Look for the fp10.1.102.64_and_9.0.289.0archive folder, open it, look for the Flash Player 10.1.102.64 folder & open and look for 101r10264 folder & open it, double click on the flashplayer101r102_64_ubmac.dmg file, choose the Install Adobe Flash Player file to install
Once done, you can use the Flash Player again for Youtube, Facebook ect
I can also do these steps for you, and have made a request via Additional Services. This is optional, and if you choose to do this, I can, with your permission, remote into your computer while you watch and do all these steps (and deal with any problems that arise during them) for you. Or if you do not choose to take this service, we can continue here. This is no problem at all. Just let me know please.
Let me know the results please