Unable to install Flashplayer: OS X Yosemite 10.10.3 - for Firefox and/or Safari - Installation fails

I've tried all methods of install I'm able to find including uninstalling and then a "clean install".  Installation failure regardless.  Tried with both Firefox 38.0.1 and Safari 8.0.6.  Followed instructions for all steps/methods here and still fails:  Installation problems | Flash Player | Mac

Any help is greatly appreciated.