hello scubadiver, you appear to be using an old version of flash that might be blocked by default because it contains security vulnerabilities. please try updating the flash plugin to the latest version and see if this can address the problem: https://get.adobe.com/flashplayer/ (uncheck the useless mcafee offer)

as for the backups - firefox only contains a built-in option to backup your bookmarks - however since all your firefox customizations and data is getting stored within one folder (your profile) it is rather easy to back that up manually: Profiles - Where Firefox stores your bookmarks, passwords and other user data

You can look at the FEBE extension;

• FEBE (Firefox Extension Backup Extension): https://addons.mozilla.org/firefox/addon/febe/

I have done exactly what you said many times and all I get is the box that says "Adobe Flash Player Installer" but the box just stays blank - forever. I even have to the task manager to stop it, and that usually takes several minutes.

in this case please try adobe's offline installer from https://www.adobe.com/products/flashplayer/distribution3.html instead (choose the windows .exe installer for plugin-based browsers)

That did it. Thanks so much.