Yeah, okay, I jumped the gun and loaded Sierra onto my oldish MacBookPro, and now, among other things, I can't install Flash, which means some important websites are inaccessible, some video won't play, and my e-cards cannot be viewed. ***? I've gone through the Flash installation process three times and it just plain disappears somewhere and the Flash things are inoperable. Do I have to uninstall Sierra and go back to Yosemite to have Flash again?