I've tried everything. I have a new MacBook Pro with Yosemite 10.10
I have downloaded every Adobe Flash Player installation file that says will work with the latest Mac system, but it just bounces on the dock. I finally found one that actually opens an installer window, but when I click "Install" the beachball spins, I let it spin all day today to see if time would help. It just kept spinning like it was at really long Beach Boys concert.
Please, someone help. Everything with video seems to use this. I've had this problem for both Safari AND Firefox.