I have a brand new Macbook Pro Retina using OSX Yosemite - have installed the most recent version of Flash player and find on BOTH Firefox (44.0.2) AND Safari (8.0.8) that on many sites I get a message saying that I need to install flashplayer or I g

I have a new Macbook Pro Retina using OSX Yosemite 10.10.5 - have installed the most recent version of Flash player and find on BOTH Firefox (44.0.2) AND Safari (8.0.8) that on many sites I get a message saying that I need to install flashplayer or I get a "frozen" msg that blocks the video content I am trying to watch that cannot be removed (see screenshot).  I am finding this problem on bigger sites like CBC, Food Network Canada and thestar.com.  Any suggestions?